toolchain/binutils: add musl libc config.sub patch to 2.23.1

Signed-off-by: Florian Fainelli <florian@openwrt.org>

SVN-Revision: 35814

toolchain/binutils/patches/2.23.1/200-musl.patch

+--- a/config.sub
++++ b/config.sub
+@@ -125,6 +125,7 @@ esac
+ maybe_os=`echo $1 | sed 's/^\(.*\)-\([^-]*-[^-]*\)$/\2/'`
+ case $maybe_os in
+   nto-qnx* | linux-gnu* | linux-android* | linux-dietlibc | linux-newlib* | \
++  linux-musl* | \
+   linux-uclibc* | uclinux-uclibc* | uclinux-gnu* | kfreebsd*-gnu* | \
+   knetbsd*-gnu* | netbsd*-gnu* | \
+   kopensolaris*-gnu* | \