arm: factorize relocate_code routine

Replace all relocate_code routines from ARM start.S files
with a single instance in file arch/arm/lib/relocate.S.
For PXA, this requires moving the dcache unlocking code
from within relocate_code into c_runtime_cpu_setup.

Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
Reviewed-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Tested-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index 5b2cb61..8ad9f66 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -39,6 +39,7 @@
 SOBJS-y += crt0.o
 
 ifndef CONFIG_SPL_BUILD
+SOBJS-y += relocate.o
 ifndef CONFIG_SYS_GENERIC_BOARD
 COBJS-y	+= board.o
 endif