snowball: Adding architecture dependent initialisation

Enabling timers and clocks in PRCMU and cleaning up mailbox.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: John Rigby <john.rigby@linaro.org>
diff --git a/arch/arm/cpu/armv7/u8500/Makefile b/arch/arm/cpu/armv7/u8500/Makefile
index 77accde..ce8af96 100644
--- a/arch/arm/cpu/armv7/u8500/Makefile
+++ b/arch/arm/cpu/armv7/u8500/Makefile
@@ -25,7 +25,7 @@
 
 LIB	= $(obj)lib$(SOC).o
 
-COBJS	= timer.o clock.o prcmu.o
+COBJS	= timer.o clock.o prcmu.o cpu.o
 SOBJS	= lowlevel.o
 
 SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)