PSCI: Fix types of definitions

Also change header guards to fix defects of MISRA C-2012 Rule 21.1.

Change-Id: Ied0d4b0e557ef6119ab669d106d2ac5d99620c57
Acked-by: Sumit Garg <sumit.garg@linaro.org>
Acked-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
diff --git a/plat/layerscape/board/ls1043/include/platform_def.h b/plat/layerscape/board/ls1043/include/platform_def.h
index 0e1cae6..46b2031 100644
--- a/plat/layerscape/board/ls1043/include/platform_def.h
+++ b/plat/layerscape/board/ls1043/include/platform_def.h
@@ -4,8 +4,8 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
-#ifndef __PLATFORM_DEF_H__
-#define __PLATFORM_DEF_H__
+#ifndef PLATFORM_DEF_H
+#define PLATFORM_DEF_H
 
 #include <common_def.h>
 #include <tzc400.h>
@@ -209,4 +209,4 @@
 #define MAX_IO_DEVICES			3
 #define MAX_IO_HANDLES			4
 
-#endif /* __PLATFORM_DEF_H__ */
+#endif /* PLATFORM_DEF_H */