m68knommu: remove unused CONFIG_MTD_KeyTechnology

Remove unused board type CONFIG_MTD_KeyTechnology.
Pointed out by Robert P. J. Day <rpjday@mindspring.com>

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