plat: xilinx: versal: Move versal_private.h to include directory

Move versal_private.h to platform specific include directory.
Also, rename it to plat_private.h instead of having platform
name. So, it can be used to common source files which needs
platform specific data.

Signed-off-by: Tejas Patel <tejas.patel@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Change-Id: I65eefbea7722ffa2760b992491c00eebef5bcef4
diff --git a/plat/xilinx/versal/aarch64/versal_common.c b/plat/xilinx/versal/aarch64/versal_common.c
index 587b797..598079c 100644
--- a/plat/xilinx/versal/aarch64/versal_common.c
+++ b/plat/xilinx/versal/aarch64/versal_common.c
@@ -1,17 +1,16 @@
 /*
- * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
+#include <plat_private.h>
 #include <common/debug.h>
 #include <drivers/generic_delay_timer.h>
 #include <lib/mmio.h>
 #include <lib/xlat_tables/xlat_tables.h>
 #include <plat/common/platform.h>
-
 #include "../versal_def.h"
-#include "../versal_private.h"
 
 /*
  * Table of regions to map using the MMU.