feat(xilinx): add feature check function for TF-A specific APIs

Currently, there is common feature check function for firmware APIs
and TF-A specific APIs. This should be separate from firmware APIs.
So add new TF-A API for feature check of TF-A specific APIs.

Signed-off-by: Jay Buddhabhatti <jay.buddhabhatti@amd.com>
Change-Id: I5585d17fb6aa1e98989d935117cca10bdb85133e
diff --git a/plat/xilinx/common/include/pm_defs.h b/plat/xilinx/common/include/pm_defs.h
index 055fa3d..30b75bc 100644
--- a/plat/xilinx/common/include/pm_defs.h
+++ b/plat/xilinx/common/include/pm_defs.h
@@ -35,6 +35,7 @@
 				       (uint32_t)XPM_NODESUBCL_DEV_PERIPH, \
 				       (uint32_t)XPM_NODETYPE_DEV_PERIPH, (IDX))
 
+#define TF_A_FEATURE_CHECK		0xa00U
 #define PM_GET_CALLBACK_DATA		0xa01U
 #define PM_GET_TRUSTZONE_VERSION	0xa03U
 #define TF_A_PM_REGISTER_SGI		0xa04U