Coverity: remove unnecessary header file includes

This patch removes unnecessary header file includes
discovered by Coverity HFA option.

Change-Id: I2827c37c1c24866c87db0e206e681900545925d4
Signed-off-by: Zelalem <zelalem.aweke@arm.com>
diff --git a/plat/arm/board/fvp/fvp_pm.c b/plat/arm/board/fvp/fvp_pm.c
index 0a62543..c47d837 100644
--- a/plat/arm/board/fvp/fvp_pm.c
+++ b/plat/arm/board/fvp/fvp_pm.c
@@ -1,11 +1,10 @@
 /*
- * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
 #include <assert.h>
-#include <errno.h>
 
 #include <arch_helpers.h>
 #include <common/debug.h>
@@ -16,7 +15,6 @@
 #include <lib/psci/psci.h>
 #include <plat/arm/common/arm_config.h>
 #include <plat/arm/common/plat_arm.h>
-#include <plat/common/platform.h>
 #include <platform_def.h>
 
 #include "fvp_private.h"