m68k: add machine and CPU definitions for ColdFire cores

Create machine and CPU definitions to support the ColdFire CPU family
members that have a virtual memory management unit.

The ColdFire V4e core contains an MMU, and it is quite different to
any other 68k family members.

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>