VT1708 does not support unsolicited response, but we need hp detect to
automute speaker. Implemented in workqueue.
Signed-off-by: Lydia Wang <lydiawang@viatech.com.cn>
Signed-off-by: Logan Li <loganli@viatech.com.cn>
Signed-off-by: Takashi Iwai <tiwai@suse.de>