Fix order of ARM platform #includes

This fix modifies the order of #includes in ARM standard platforms
to meet the ARM TF coding standard.

Change-Id: Ide19aad6233babda4eea2d17d49e523645fed1b2
Signed-off-by: Isla Mitchell <isla.mitchell@arm.com>
diff --git a/plat/arm/common/arm_bl2_setup.c b/plat/arm/common/arm_bl2_setup.c
index e5619b7..b7621b8 100644
--- a/plat/arm/common/arm_bl2_setup.c
+++ b/plat/arm/common/arm_bl2_setup.c
@@ -12,8 +12,8 @@
 #include <debug.h>
 #include <desc_image_load.h>
 #include <plat_arm.h>
-#include <platform_def.h>
 #include <platform.h>
+#include <platform_def.h>
 #include <string.h>
 #include <utils.h>