ARM: mvebu: Fix pmsu compilation when ARMv6 is selected

When compiling for multiplatform for both ARMv6 and ARMv7, the default compiler
flags are for ARMv6, and we will get:

  /tmp/ccwDEzd0.s: Assembler messages:
  /tmp/ccwDEzd0.s:639: Error: selected processor does not support ARM mode `isb '
  /tmp/ccwDEzd0.s:645: Error: selected processor does not support ARM mode `isb '
  /tmp/ccwDEzd0.s:646: Error: selected processor does not support ARM mode `dsb '
  /tmp/ccwDEzd0.s:695: Error: selected processor does not support ARM mode `isb '
  make[1]: *** [arch/arm/mach-mvebu/pmsu.o] Error 1

Fix this in a similar manner than done previously in commit
72533b77, by specifying ARMv7 flags for pmsu.o.
Signed-off-by: Vincent Stehlé <vincent.stehle@laposte.net>
Link: https://lkml.kernel.org/r/1399407782-29091-1-git-send-email-vincent.stehle@laposte.net
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

arch/arm/mach-mvebu/Makefile

@@ -2,6 +2,7 @@ ccflags-$(CONFIG_ARCH_MULTIPLATFORM) := -I$(srctree)/$(src)/include \
 	-I$(srctree)/arch/arm/plat-orion/include
 
 AFLAGS_coherency_ll.o		:= -Wa,-march=armv7-a
+CFLAGS_pmsu.o			:= -march=armv7-a
 
 obj-y				 += system-controller.o mvebu-soc-id.o