au1xmmc: codingstyle tidying.

Clean up the codebase, no functional changes.
- merge the au1xmmc.h header contents into the driver file,
- indentation, spelling and style fixes.

Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>