Patch from Lennert Buytenhek

The alignment trap handler in arch/arm/mm/alignment.c performs halfword
and word accesses by translating them into byte accessing and then
combining the pieces.  However, it assumes little-endian byte ordering
in doing so, which causes unaligned accesses on big-endian platforms
to erroneously load or store byteswapped data.
This patch was pulled from an old 2.4 -ds tree, and appears to fix the
issue.  It was submitted for 2.4 at the time (ARM patch ID 1205/1206),
but rejected since big-endian ARM platforms are not supported in 2.4.

Signed-off-by: Lennert Buytenhek
Signed-off-by: Russell King