m68knommu: unaligned.h fix for M68000 core

This patch fixes unaligned memory access for the 68000 core based cpu's.

Some time ago, my cpu (68000) was raising address/bus error's when mounting
cifs shares (didn't bother to debug it at the time). After developing the
MMC/SD card driver I was having the same issue when mounting the vfat fs.

I've traced the issue down to the 'unaligned.h' file. (I guess nobody has
ever used unaligned.h back in the 68328 'era'.

Signed-off-by: Luis Alves <ljalvs@gmail.com>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>