ALSA: hda/realtek - Enable the headset-mic on a Xiaomi's laptop

The headset on this machine is not defined, after applying the quirk
ALC256_FIXUP_ASUS_HEADSET_MIC, the headset-mic works well

Signed-off-by: Meng Tang <tangmeng@uniontech.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220713094133.9894-1-tangmeng@uniontech.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>