arch: add basic m68k support

Signed-off-by: Remy Bohmer <linux@bohmer.net>
[yann.morin.1998@anciens.enib.fr: use defaults for CT_TARGET_ARCH]
Signed-off-by: "Yann E. MORIN <yann.morin.1998@anciens.enib.fr>

 reporter_name="Matthias KAEHLCKE"

 reporter_url="http://sourceware.org/ml/crossgcc/2008-08/msg00055.html"

 reporter_comment=""