samples: add new m68k-unknown-uclinux-uclibc sample

Signed-off-by: "Esben Haabendal" <esben@haabendal.dk>
[yann.morin.1998@free.fr: upgrade to using gcc-4.7.2]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Message-Id: <87r4pod1hm.fsf@arh128.prevas.dk>
PatchWork-Id: 187182

 # Compute s390-specific values

 CT_DoArchTupleValues() {

     # That's the only thing to override

     if [ "${CT_ARCH_64}" = "y" ]; then

         CT_TARGET_ARCH="s390x"

     fi

 }