m68k: add code to setup a ColdFire 54xx platform when MMU enabled

We use the same setup code for ColdFire MMU enabled platforms as
standard m68k. So add support for it to setup our 54xx ColdFire
platforms. They do not support the same bootinfo parsing as other
m68k platforms.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Matt Waddel <mwaddel@yahoo.com>
Acked-by: Kurt Mahan <kmahan@xmission.com>