arm: fix -march for ARM11

In GCC 9 support for the Armv5 and Armv5E architectures (which have no
known implementations) has been removed, cf.
https://gcc.gnu.org/gcc-9/changes.html

ARM11 is an armv6 implementation. So change the architecture flag for the
compiler to armv6 for ARM11.

Suggested-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 5384981..60af7e3 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -12,8 +12,8 @@
 arch-$(CONFIG_CPU_ARM946ES)	=-march=armv5te
 arch-$(CONFIG_CPU_SA1100)	=-march=armv4
 arch-$(CONFIG_CPU_PXA)		=
-arch-$(CONFIG_CPU_ARM1136)	=-march=armv5
-arch-$(CONFIG_CPU_ARM1176)	=-march=armv5t
+arch-$(CONFIG_CPU_ARM1136)	=-march=armv6
+arch-$(CONFIG_CPU_ARM1176)	=-march=armv6
 arch-$(CONFIG_CPU_V7A)		=$(call cc-option, -march=armv7-a, \
 				 $(call cc-option, -march=armv7))
 arch-$(CONFIG_CPU_V7M)		=-march=armv7-m