AC97 Codec Core,Intel8x0 driver,Intel8x0-modem driver
Fixed the detection of sample rates with no VRA support.

- Changed ac97bus->vra to ac97bus->no_vra to indicate the VRA is NOT
  supported.
- In the case of no_vra=1, only 48k is set as the possible rates in
  snd_ac97_pcm_assign().
Signed-off-by: Takashi Iwai <tiwai@suse.de>