[PATCH] Add CXT48 to modem black list in ac97

The following patch works around the misdetection of the CXT48 codec as a
modem by the OSS ac97 driver.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>