linux-phytec-ti

m68knommu: fix m548x_wdt.c compilation after headers renaming

m548x headers were renamed to m54xx, but m548x_wdt.c still uses the
old names.  Fix that.

Signed-off-by: Philippe De Muyter <phdm@macqel.be>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>