PSCI: Fix MISRA defects in platform code

Fix violations of MISRA C-2012 Rules 10.1, 10.3, 13.3, 14.4, 17.7 and
17.8.

Change-Id: I6c9725e428b5752f1d80684ec29cb6c52a5c0c2d
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
diff --git a/include/plat/common/platform.h b/include/plat/common/platform.h
index cd17a00..12eac60 100644
--- a/include/plat/common/platform.h
+++ b/include/plat/common/platform.h
@@ -4,8 +4,8 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
-#ifndef __PLATFORM_H__
-#define __PLATFORM_H__
+#ifndef PLATFORM_H
+#define PLATFORM_H
 
 #include <psci.h>
 #include <stdint.h>
@@ -401,5 +401,4 @@
 
 #endif /* __ENABLE_PLAT_COMPAT__ */
 
-#endif /* __PLATFORM_H__ */
-
+#endif /* PLATFORM_H */