[ALSA] hda-codec - Add support for VIA VT1708B HD audio codec

This patch adds support for VIA new HD audio codec, VT1708B.
Signed-off-by: Josepch Chan <josephchan@via.com.tw>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>