MAINTAINERS: update m68knommu patterns

Commit 66d857b0 ("m68k: merge m68k and m68knommu arch directories")
moved the files around.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>