m68k: add cache support for V4e ColdFire cores running with MMU enabled

Add code to deal with instruction, data and branch caches of the V4e
ColdFire cores when they are running with the MMU enabled.

This code is loosely based on Freescales changes for the caches of the
V4e ColdFire in the 2.6.25 kernel BSP. That code was originally by
Kurt Mahan <kmahan@freescale.com> (now <kmahan@xmission.com>).

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>