The MCF548x have the same cache control registers as the MCF5407.
Extract the bit definitions for the ACR and CACR registers from m5407sim.h
and move them to a new file m54xxacr.h.  Those definitions are not used
anywhere yet, so no other file is involved.  This is a preparation for
m54xx cache support cleanup.
Signed-off-by: Philippe De Muyter <phdm@macqel.be>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>