arm: mach-rmobile: Drop <common.h>

For most source files we can just drop <common.h>. We need to add an
include for <asm/u-boot.h> in a couple of places. Also sort the include
list in memmap-gen3.c while we're here.

Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>