m68knommu: remove is_in_rom() function

Remove is_in_rom() function.  It doesn't actually serve the purpose it was
intended to.  If you look at the use of it _access_ok() (which is the only use
of it) then it is obvious that most of memory is marked as access_ok.  No
point having is_in_rom() then, so remove it.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>