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/package/collectd/Config.in

@@ -285,6 +285,11 @@ config BR2_PACKAGE_COLLECTD_HUGEPAGES
 	help
 	  Reports the number of used and free hugepages on Linux.
 
+config BR2_PACKAGE_COLLECTD_INFINIBAND
+	bool "infiniband"
+	help
+	  Attributes and counters for each port on each IB device.
+
 config BR2_PACKAGE_COLLECTD_INTERFACE
 	bool "interface"
 	help
@@ -321,11 +326,21 @@ config BR2_PACKAGE_COLLECTD_LOAD
 	help
 	  Collects the system load.
 
+config BR2_PACKAGE_COLLECTD_LOGPARSER
+	bool "logparser"
+	help
+	  Plugin for filtering and parsing log messages.
+
 config BR2_PACKAGE_COLLECTD_MD
 	bool "md"
 	help
 	  Collects software-RAID device information.
 
+config BR2_PACKAGE_COLLECTD_MDEVENTS
+	bool "mdevents"
+	help
+	  Events from md (Linux Software RAID) devices.
+
 config BR2_PACKAGE_COLLECTD_MEMCACHEC
 	bool "memcachec"
 	depends on BR2_INSTALL_LIBSTDCPP
@@ -498,6 +513,11 @@ config BR2_PACKAGE_COLLECTD_SWAP
 	help
 	  Collects the amount of memory currently written to disk.
 
+config BR2_PACKAGE_COLLECTD_SYNPROXY
+	bool "synproxy"
+	help
+	  Synproxy stats plugin.
+
 config BR2_PACKAGE_COLLECTD_TABLE
 	bool "table"
 	help
@@ -525,6 +545,16 @@ config BR2_PACKAGE_COLLECTD_THERMAL
 	help
 	  Reads ACPI thermal zone information.
 
+config BR2_PACKAGE_COLLECTD_UBI
+	bool "ubi"
+	help
+	  UBI (Unsorted Block Images) is an erase block management layer
+	  for flash memory devices. UBI serves two purposes, tracking
+	  NAND flash bad blocks and providing wear leveling.
+	  This plugin collects some stats about UBI devices:
+	   * bad physical underlying blocks (bad_peb_count)
+	   * max erase counter value (max_ec)
+
 config BR2_PACKAGE_COLLECTD_UPTIME
 	bool "uptime"
 	help