feat(plat/sgi): enable use of PSCI extended state ID format

The SGI/RD platforms have been using PSCI state ID format as defined in
PSCI version prior to 1.0. This is being changed and the PSCI extended
state ID format as defined in PSCI version 1.1 is being adapted. In
addition to this, the use of Arm recommended PSCI state ID encoding is
enabled as well.

Change-Id: I2be8a9820987a96b23f4281563b6fa22db48fa5f
Signed-off-by: Pranav Madhu <pranav.madhu@arm.com>
diff --git a/plat/arm/css/sgi/sgi-common.mk b/plat/arm/css/sgi/sgi-common.mk
index 1e2054f..8baf4ee 100644
--- a/plat/arm/css/sgi/sgi-common.mk
+++ b/plat/arm/css/sgi/sgi-common.mk
@@ -65,6 +65,8 @@
 override NEED_BL2U		:=	no
 override ARM_BL31_IN_DRAM	:=	1
 override ARM_PLAT_MT		:=	1
+override PSCI_EXTENDED_STATE_ID	:=	1
+override ARM_RECOM_STATE_ID_ENC	:=	1
 
 # System coherency is managed in hardware
 HW_ASSISTED_COHERENCY	:=	1