Update buildroot to 2021.02.3 (#1422)

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

buildroot/package/libxslt/0001-Fix-xml2-config-check-in-configure-script.patch

@@ -0,0 +1,31 @@
+From 90c34c8bb90e095a8a8fe8b2ce368bd9ff1837cc Mon Sep 17 00:00:00 2001
+From: Nick Wellnhofer <wellnhofer@aevum.de>
+Date: Fri, 15 Nov 2019 11:53:11 +0100
+Subject: [PATCH] Fix xml2-config check in configure script
+
+A 'print' option has never been supported. After a recent change to
+libxml2, invalid options cause xml2-config to fail.
+
+[Retrieved from:
+https://gitlab.gnome.org/GNOME/libxslt/-/commit/90c34c8bb90e095a8a8fe8b2ce368bd9ff1837cc]
+Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+---
+ configure.ac | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/configure.ac b/configure.ac
+index 3da57b18..585b9d7c 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -548,7 +548,7 @@ dnl make sure xml2-config is executable,
+ dnl test version and init our variables
+ dnl
+ 
+-if test "x$LIBXML_LIBS" = "x" && ${XML_CONFIG} --libs print > /dev/null 2>&1
++if test "x$LIBXML_LIBS" = "x" && ${XML_CONFIG} --libs > /dev/null 2>&1
+ then
+     AC_MSG_CHECKING(for libxml libraries >= $LIBXML_REQUIRED_VERSION)
+     XMLVERS=`$XML_CONFIG --version`
+-- 
+GitLab
+