ALSA: hda - VIA: Fix invalid A-A path volume adjust issue

Modify vt_auto_create_analog_input_ctls() function to fix invalid a-a path
volume adjust issue for VT1708S, VT1702 and VT1716S codecs.

Signed-off-by: Lydia Wang <lydiawang@viatech.com.cn>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>