feat(morello): add cpuidle support

This patch adds necessary device-tree idle state definitions and enables
relevant platform makefile options.

Co-authored-by: Karl Meakin <karl.meakin@arm.com>
Signed-off-by: sahil <sahil@arm.com>
Change-Id: Iaf95867095f0514ec3994b9c9efd9756ed49ef43
diff --git a/plat/arm/board/morello/platform.mk b/plat/arm/board/morello/platform.mk
index 0ae7693..12ffb5a 100644
--- a/plat/arm/board/morello/platform.mk
+++ b/plat/arm/board/morello/platform.mk
@@ -89,6 +89,9 @@
 
 override ARM_BL31_IN_DRAM		:=	1
 
+override PSCI_EXTENDED_STATE_ID		:=	1
+override ARM_RECOM_STATE_ID_ENC		:=	1
+
 # Errata workarounds:
 ERRATA_N1_1868343			:=	1