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

Move versal_def.h to platform specific include directory.
Also, update source file to include header file from updated
path of versal_def.h

Signed-off-by: Tejas Patel <tejas.patel@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Change-Id: I313592a17552843b9cc7048f31bcaaefa40ffd91
diff --git a/plat/xilinx/versal/include/platform_def.h b/plat/xilinx/versal/include/platform_def.h
index 0c4b954..e61929c 100644
--- a/plat/xilinx/versal/include/platform_def.h
+++ b/plat/xilinx/versal/include/platform_def.h
@@ -1,5 +1,5 @@
 /*
- * 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
  */
@@ -8,8 +8,7 @@
 #define PLATFORM_DEF_H
 
 #include <arch.h>
-
-#include "../versal_def.h"
+#include "versal_def.h"
 
 /*******************************************************************************
  * Generic platform constants