xilinx: versal: Implement PLL related PM APIs

Implement below PLL related APIs:
- Set PLL parameter
- Get PLL parameter
- Set PLL mode
- Get PLL mode

Signed-off-by: Tejas Patel <tejas.patel@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Change-Id: I37749d05cdb73641d32da120d319cf36df97c73f
diff --git a/plat/xilinx/versal/pm_service/pm_defs.h b/plat/xilinx/versal/pm_service/pm_defs.h
index e9aa512..ce2605a 100644
--- a/plat/xilinx/versal/pm_service/pm_defs.h
+++ b/plat/xilinx/versal/pm_service/pm_defs.h
@@ -48,6 +48,10 @@
 #define PM_CLOCK_GETRATE		42U
 #define PM_CLOCK_SETPARENT		43U
 #define PM_CLOCK_GETPARENT		44U
+#define PM_PLL_SET_PARAMETER		48U
+#define PM_PLL_GET_PARAMETER		49U
+#define PM_PLL_SET_MODE			50U
+#define PM_PLL_GET_MODE			51U
 
 /*********************************************************************
  * Enum definitions