fix(zynqmp): resolve the misra 4.6 warnings

MISRA Violation: MISRA-C:2012 R.4.6
- Using basic numerical type int rather than a typedef
that includes size and signedness information.

Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@xilinx.com>
Change-Id: I9fb686e7aa2b85af6dfcb7bb5f87eddf469fb85c
diff --git a/plat/xilinx/zynqmp/plat_topology.c b/plat/xilinx/zynqmp/plat_topology.c
index aab24aa..41add9f 100644
--- a/plat/xilinx/zynqmp/plat_topology.c
+++ b/plat/xilinx/zynqmp/plat_topology.c
@@ -3,10 +3,11 @@
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
+#include <stdint.h>
 
-static const unsigned char plat_power_domain_tree_desc[] = {1, 4};
+static const uint8_t plat_power_domain_tree_desc[] = {1, 4};
 
-const unsigned char *plat_get_power_domain_tree_desc(void)
+const uint8_t *plat_get_power_domain_tree_desc(void)
 {
 	return plat_power_domain_tree_desc;
 }