Split platform.h into separate headers

Previously, platform.h contained many declarations and definitions
used for different purposes. This file has been split so that:

* Platform definitions used by common code that must be defined
  by the platform are now in platform_def.h. The exact include
  path is exported through $PLAT_INCLUDES in the platform makefile.

* Platform definitions specific to the FVP platform are now in
  /plat/fvp/fvp_def.h.

* Platform API declarations specific to the FVP platform are now
  in /plat/fvp/fvp_private.h.

* The remaining platform API declarations that must be ported by
  each platform are still in platform.h but this file has been
  moved to /include/plat/common since this can be shared by all
  platforms.

Change-Id: Ieb3bb22fbab3ee8027413c6b39a783534aee474a
diff --git a/bl2/bl2.ld.S b/bl2/bl2.ld.S
index 9f02e92..e348d4f 100644
--- a/bl2/bl2.ld.S
+++ b/bl2/bl2.ld.S
@@ -28,7 +28,7 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <platform.h>
+#include <platform_def.h>
 
 OUTPUT_FORMAT(PLATFORM_LINKER_FORMAT)
 OUTPUT_ARCH(PLATFORM_LINKER_ARCH)