ALSA: hda - display audio call sync_audio_rate callback

For display audio, call the sync_audio_rate callback function
to do the synchronization between gfx driver and audio driver.

Signed-off-by: Libin Yang <libin.yang@intel.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>