Bump Buildroot to 2021.02-rc3 (#1260)

* Rebase patches to Buildroot 2021.02-rc3

* Update Buildroot to 2021.02-rc3

* Declare Kernel headers to be Linux version 5.10 (since they are, and new Buildroot knows about 5.10)

buildroot/support/config-fragments/autobuild/toolchain-configs.csv

@@ -4,16 +4,16 @@
 # Toolchains used by default by test-pkg:
 
 # Test a regular uClibc toolchain
-support/config-fragments/autobuild/br-arm-full.config,x86_64
+support/config-fragments/autobuild/bootlin-armv5-uclibc.config,x86_64
 
 # Test a toolchain with glibc and a very recent gcc version
-support/config-fragments/autobuild/br-arm-cortex-a9-glibc.config,x86_64
+support/config-fragments/autobuild/bootlin-armv7-glibc.config,x86_64
 
 # Test a noMMU toolchain with no dynamic library support
-support/config-fragments/autobuild/br-arm-cortex-m4-full.config,x86_64
+support/config-fragments/autobuild/bootlin-armv7m-uclibc.config,x86_64
 
 # Test a musl toolchain
-support/config-fragments/autobuild/br-x86-64-musl.config,x86_64
+support/config-fragments/autobuild/bootlin-x86-64-musl.config,x86_64
 
 # Test a MMU toolchain without dynamic library support
 support/config-fragments/autobuild/br-arm-full-static.config,x86_64
@@ -24,44 +24,44 @@ support/config-fragments/autobuild/sourcery-arm.config,x86
 # Toolchains used by test-pkg only when the '-a' option is passed:
 support/config-fragments/autobuild/andes-nds32.config,x86
 support/config-fragments/autobuild/arm-aarch64.config,x86_64
+support/config-fragments/autobuild/bootlin-aarch64-glibc.config,x86_64
+support/config-fragments/autobuild/bootlin-arcle-hs38-uclibc.config,x86_64
+support/config-fragments/autobuild/bootlin-armv7-musl.config,x86_64
+support/config-fragments/autobuild/bootlin-m68k-68040-uclibc.config,x86_64
+support/config-fragments/autobuild/bootlin-m68k-5208-uclibc.config,x86_64
+support/config-fragments/autobuild/bootlin-microblazeel-uclibc.config,x86_64
+support/config-fragments/autobuild/bootlin-mipsel-uclibc.config,x86_64
+support/config-fragments/autobuild/bootlin-mipsel32r6-glibc.config,x86_64
+support/config-fragments/autobuild/bootlin-nios2-glibc.config,x86_64
+support/config-fragments/autobuild/bootlin-openrisc-uclibc.config,x86_64
+support/config-fragments/autobuild/bootlin-powerpc64le-power8-glibc.config,x86_64
+support/config-fragments/autobuild/bootlin-powerpc-e500mc-uclibc.config,x86_64
+support/config-fragments/autobuild/bootlin-riscv32-glibc.config,x86_64
+support/config-fragments/autobuild/bootlin-riscv64-glibc.config,x86_64
+support/config-fragments/autobuild/bootlin-riscv64-musl.config,x86_64
+support/config-fragments/autobuild/bootlin-sh4-uclibc.config,x86_64
+support/config-fragments/autobuild/bootlin-sparc-uclibc.config,x86_64
+support/config-fragments/autobuild/bootlin-sparc64-glibc.config,x86_64
 support/config-fragments/autobuild/bootlin-x86-64-glibc.config,x86_64
-support/config-fragments/autobuild/br-aarch64-glibc.config,x86_64
+support/config-fragments/autobuild/bootlin-x86-64-uclibc.config,x86_64
+support/config-fragments/autobuild/bootlin-xtensa-uclibc.config,x86_64
 support/config-fragments/autobuild/br-arc-full-internal.config,any
 support/config-fragments/autobuild/br-arc-internal-glibc.config,any
-support/config-fragments/autobuild/br-arcle-hs38.config,x86_64
 support/config-fragments/autobuild/br-arm-basic.config,x86_64
-support/config-fragments/autobuild/br-arm-cortex-a9-musl.config,x86_64
 support/config-fragments/autobuild/br-arm-full-nothread.config,x86_64
 support/config-fragments/autobuild/br-arm-internal-full.config,any
 support/config-fragments/autobuild/br-arm-internal-glibc.config,any
 support/config-fragments/autobuild/br-arm-internal-musl.config,any
 support/config-fragments/autobuild/br-i386-pentium4-full.config,x86_64
 support/config-fragments/autobuild/br-i386-pentium-mmx-musl.config,x86_64
-support/config-fragments/autobuild/br-m68k-5208-full.config,x86_64
-support/config-fragments/autobuild/br-m68k-68040-full.config,x86_64
-support/config-fragments/autobuild/br-microblazeel-full.config,x86_64
 support/config-fragments/autobuild/br-microblazeel-full-internal.config,any
 support/config-fragments/autobuild/br-mips64-n64-full.config,x86_64
-support/config-fragments/autobuild/br-mips32r6-el-hf-glibc.config,x86_64
 support/config-fragments/autobuild/br-mips64r6-el-hf-glibc.config,x86_64
-support/config-fragments/autobuild/br-mipsel-o32-full.config,x86_64
-support/config-fragments/autobuild/br-nios2-glibc.config,x86_64
-support/config-fragments/autobuild/br-openrisc-uclibc.config,x86_64
 support/config-fragments/autobuild/br-powerpc-603e-basic-cpp.config,x86_64
-support/config-fragments/autobuild/br-powerpc64le-power8-glibc.config,x86_64
 support/config-fragments/autobuild/br-powerpc64-power7-glibc.config,x86_64
-support/config-fragments/autobuild/br-powerpc-e500mc-full.config,x86_64
 support/config-fragments/autobuild/br-powerpc-internal-full.config,any
-support/config-fragments/autobuild/br-riscv32.config,x86_64
-support/config-fragments/autobuild/br-riscv64.config,x86_64
 support/config-fragments/autobuild/br-riscv64-full-internal.config,any
-support/config-fragments/autobuild/br-riscv64-musl.config,x86_64
 support/config-fragments/autobuild/br-s390x-z13-internal-glibc.config,any
-support/config-fragments/autobuild/br-sh4-full.config,x86_64
-support/config-fragments/autobuild/br-sparc-uclibc.config,x86_64
-support/config-fragments/autobuild/br-sparc64-glibc.config,x86_64
-support/config-fragments/autobuild/br-x86-64-core2-full.config,x86_64
-support/config-fragments/autobuild/br-xtensa-full.config,x86_64
 support/config-fragments/autobuild/br-xtensa-full-internal.config,any
 support/config-fragments/autobuild/linaro-aarch64.config,x86
 support/config-fragments/autobuild/linaro-aarch64-be.config,x86