Update buildroot to 2021.02.4 (#1522)

Signed-off-by: Stefan Agner <stefan@agner.ch>

buildroot/support/testing/tests/package/test_uboot_openssl_pkgconfig.py

@@ -0,0 +1,19 @@
+import os
+
+import infra.basetest
+
+
+class TestUbootOpensslPkgConfig(infra.basetest.BRTest):
+    config = infra.basetest.MINIMAL_CONFIG + \
+        """
+        BR2_x86_64=y
+        BR2_x86_atom=y
+        BR2_PACKAGE_OPENSSL=y
+        BR2_TARGET_UBOOT=y
+        BR2_TARGET_UBOOT_BOARD_DEFCONFIG="efi-x86_payload64"
+        BR2_TARGET_UBOOT_NEEDS_OPENSSL=y
+        """
+
+    def test_run(self):
+        img = os.path.join(self.builddir, "images", "u-boot.bin")
+        self.assertTrue(os.path.exists(img))