[ALSA] hda-intel - Add ATI RS780,R600 HDMI audio support

This patch is for ATI RS780 and R600 HDMI support.

Signed-off-by: Wolke Liu <wolke.liu@amd.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>