refactor(xilinx): move pm_defs.h to common place

Moved pm_defs.h file to common place so that it can be used for
Versal NET and ZynqMP. Also moved common code from zynqmp_pm_defs.h to
common place.

Signed-off-by: Jay Buddhabhatti <jay.buddhabhatti@amd.com>
Change-Id: I2ee1e72258c6052cdd6467cdbcf4009afb98da49
diff --git a/plat/xilinx/versal_net/plat_psci.c b/plat/xilinx/versal_net/plat_psci.c
index c5833a9..8bb9bda 100644
--- a/plat/xilinx/versal_net/plat_psci.c
+++ b/plat/xilinx/versal_net/plat_psci.c
@@ -1,7 +1,7 @@
 /*
  * Copyright (c) 2018-2020, ARM Limited and Contributors. All rights reserved.
  * Copyright (c) 2021-2022, Xilinx, Inc. All rights reserved.
- * Copyright (C) 2022, Advanced Micro Devices, Inc. All rights reserved.
+ * Copyright (c) 2022-2023, Advanced Micro Devices, Inc. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -17,11 +17,10 @@
 #include <plat_arm.h>
 
 #include <plat_private.h>
+#include <pm_defs.h>
 
 #define PM_RET_ERROR_NOFEATURE U(19)
 
-#define PM_IOCTL	34U
-
 static uintptr_t versal_net_sec_entry;
 
 static void zynqmp_cpu_standby(plat_local_state_t cpu_state)