Update buildroot to 2021.02.3 (#1422)

Signed-off-by: Stefan Agner <stefan@agner.ch>
(cherry picked from commit 9c8172df40)

buildroot/package/llvm/0001-nfc-Fix-missing-include.patch

@@ -0,0 +1,24 @@
+From b498303066a63a203d24f739b2d2e0e56dca70d1 Mon Sep 17 00:00:00 2001
+From: serge-sans-paille <sguelton@redhat.com>
+Date: Tue, 10 Nov 2020 14:55:25 +0100
+Subject: [PATCH] [nfc] Fix missing include
+
+[Retrieved (and backported) from:
+https://github.com/llvm/llvm-project/commit/b498303066a63a203d24f739b2d2e0e56dca70d1]
+Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+---
+ llvm/utils/benchmark/src/benchmark_register.h | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/utils/benchmark/src/benchmark_register.h b/utils/benchmark/src/benchmark_register.h
+index 0705e219f2fa2..4caa5ad4da079 100644
+--- a/utils/benchmark/src/benchmark_register.h
++++ b/utils/benchmark/src/benchmark_register.h
+@@ -1,6 +1,7 @@
+ #ifndef BENCHMARK_REGISTER_H
+ #define BENCHMARK_REGISTER_H
+ 
++#include <limits>
+ #include <vector>
+ 
+ #include "check.h"