zynqmp : pm : Adds new zynqmp-pm api SMC call for register access

This patch adds new zynqmp-pm api to provide read/write access to
CSU or PMU global registers.

Signed-off-by: Kalyani Akula <kalyania@xilinx.com>
Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Change-Id: I4fd52eb732fc3e6a8bccd96cad7dc090b2161042
diff --git a/plat/xilinx/zynqmp/pm_service/pm_defs.h b/plat/xilinx/zynqmp/pm_service/pm_defs.h
index 4776d42..8b28807 100644
--- a/plat/xilinx/zynqmp/pm_service/pm_defs.h
+++ b/plat/xilinx/zynqmp/pm_service/pm_defs.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -97,6 +97,8 @@
 	PM_PLL_GET_PARAMETER,
 	PM_PLL_SET_MODE,
 	PM_PLL_GET_MODE,
+	/* PM Register Access API */
+	PM_REGISTER_ACCESS,
 	PM_API_MAX
 };