feat(fvp): enable support for PSCI OS-initiated mode

Change-Id: I4cd6d2bd7ec7f581bd525d5323a3b54e855e2e51
Signed-off-by: Wing Li <wingers@google.com>
diff --git a/include/plat/arm/common/plat_arm.h b/include/plat/arm/common/plat_arm.h
index 494e470..34f913b 100644
--- a/include/plat/arm/common/plat_arm.h
+++ b/include/plat/arm/common/plat_arm.h
@@ -125,6 +125,12 @@
 #define ARM_LOCAL_PSTATE_WIDTH		4
 #define ARM_LOCAL_PSTATE_MASK		((1 << ARM_LOCAL_PSTATE_WIDTH) - 1)
 
+#if PSCI_OS_INIT_MODE
+#define ARM_LAST_AT_PLVL_MASK		(ARM_LOCAL_PSTATE_MASK <<	\
+					 (ARM_LOCAL_PSTATE_WIDTH *	\
+					  (PLAT_MAX_PWR_LVL + 1)))
+#endif /* __PSCI_OS_INIT_MODE__ */
+
 /* Macros to construct the composite power state */
 
 /* Make composite power state parameter till power level 0 */