feat(xilinx): add handler for power down req sgi irq

On receiving CPU power down callback, TF-A raises SGI interrupt to all active
cores to power down each active cores. Add handler for this SGI IRQ.

By default TF-A uses SGI 6 for CPU power down request. This can be
configurable through CPU_PWRDWN_SGI build flag.

e.g., If user wants to use SGI 7 instead of SGI 6 then provide build
flag CPU_PWRDWN_SGI=7

Signed-off-by: Jay Buddhabhatti <jay.buddhabhatti@amd.com>
Change-Id: Id0df32187d1de3f0af4486eb4d4930cb3ab01dbd
diff --git a/plat/xilinx/versal_net/include/platform_def.h b/plat/xilinx/versal_net/include/platform_def.h
index 334714b..8cb7deb 100644
--- a/plat/xilinx/versal_net/include/platform_def.h
+++ b/plat/xilinx/versal_net/include/platform_def.h
@@ -10,6 +10,7 @@
 #define PLATFORM_DEF_H
 
 #include <arch.h>
+#include <plat_common.h>
 #include "versal_net_def.h"
 
 /*******************************************************************************
@@ -124,6 +125,8 @@
 
 #define PLAT_ARM_G0_IRQ_PROPS(grp) \
 	INTR_PROP_DESC(PLAT_VERSAL_IPI_IRQ, GIC_HIGHEST_SEC_PRIORITY, grp, \
+			GIC_INTR_CFG_EDGE), \
+	INTR_PROP_DESC(CPU_PWR_DOWN_REQ_INTR, GIC_HIGHEST_SEC_PRIORITY, grp, \
 			GIC_INTR_CFG_EDGE)
 
 #define IRQ_MAX		200U
diff --git a/plat/xilinx/versal_net/platform.mk b/plat/xilinx/versal_net/platform.mk
index b2aceca..da91abc 100644
--- a/plat/xilinx/versal_net/platform.mk
+++ b/plat/xilinx/versal_net/platform.mk
@@ -21,6 +21,8 @@
 GIC_ENABLE_V4_EXTN :=  0
 GICV3_SUPPORT_GIC600 := 1
 TFA_NO_PM := 0
+CPU_PWRDWN_SGI ?= 6
+$(eval $(call add_define_val,CPU_PWR_DOWN_REQ_INTR,ARM_IRQ_SEC_SGI_${CPU_PWRDWN_SGI}))
 
 override CTX_INCLUDE_AARCH32_REGS    := 0