ALSA: hda/realtek - Restore default value for ALC668

Restore the registers to prevent the abnormal digital power supply
rising ratio/sequence to the codec and causing the incorrect default
codec register restoration during initialization.

Signed-off-by: Kailang Yang <kailang@realtek.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Merge branch 'for-linus'