Include missing header in arm_bl2_setup.c

Change-Id: I4108ce8d1fe7d3fd51a5a96d43b9134c23b8399b
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>

plat/arm/common/arm_bl2_setup.c

@@ -13,6 +13,7 @@
 #include <desc_image_load.h>
 #include <plat_arm.h>
 #include <platform_def.h>
+#include <platform.h>
 #include <string.h>
 #include <utils.h>