plat: xilinx: zynqmp: Move zynqmp_private.h to include directory

Move zynqmp_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>
Reviewed-by: Siva Durga Prasad Paladugu <siva.durga.paladugu@xilinx.com>
Signed-off-by: Jolly Shah <jollys@xilinx.com>
diff --git a/plat/xilinx/zynqmp/aarch64/zynqmp_common.c b/plat/xilinx/zynqmp/aarch64/zynqmp_common.c
index 23c02e0..8ff6c43 100644
--- a/plat/xilinx/zynqmp/aarch64/zynqmp_common.c
+++ b/plat/xilinx/zynqmp/aarch64/zynqmp_common.c
@@ -11,9 +11,9 @@
 #include <drivers/generic_delay_timer.h>
 #include <lib/mmio.h>
 #include <lib/xlat_tables/xlat_tables.h>
+#include <plat_private.h>
 #include <plat/common/platform.h>
 
-#include "../zynqmp_private.h"
 #include "pm_api_sys.h"
 
 /*