AC97 Codec Core
Unfortunately, on newer xboxes, the chip reports less info than
before, making another change necessary - this change is backwards
compatible, and doesn't break earlier xboxes, of course.

The patch is originally from Ed Hucek <hostmaster@ed-soft.at>.
Signed-off-by: David Pye <dmp@davidmpye.dyndns.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>