ARM: HYP/non-sec: add generic ARMv7 PSCI code

Implement core support for PSCI. As this is generic code, it doesn't
implement anything really useful (all the functions are returning
Not Implemented).

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>
diff --git a/arch/arm/cpu/armv7/Makefile b/arch/arm/cpu/armv7/Makefile
index 232118d..735c4ad 100644
--- a/arch/arm/cpu/armv7/Makefile
+++ b/arch/arm/cpu/armv7/Makefile
@@ -23,6 +23,10 @@
 obj-y	+= virt-v7.o
 endif
 
+ifneq ($(CONFIG_ARMV7_PSCI),)
+obj-y	+= psci.o
+endif
+
 obj-$(CONFIG_KONA) += kona-common/
 obj-$(CONFIG_OMAP_COMMON) += omap-common/
 obj-$(CONFIG_SYS_ARCH_TIMER) += arch_timer.o