Fixes for big-endian systems in soundcard.h and awe_voice.h

This patch fixes the AFMT_S16_NE (include/linux/soundcard.h) and AWE_PATCH
(awe_voice.h) macros on big-endian systems.

It also moves _PATCHKEY into a new file, patchkey.h, in order to remove a
duplicate definition of it from awe_voice.h.
Signed-off-by: NStuart Brady <sdbrady@ntlworld.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>