Common I/O layer changes:
 - Check if AIF is available on hardware before enabling
   the AIF time delay disablement facility.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>