ALSA: hda/realtek - The Mic on a RedmiBook doesn't work

ALSA: hda/realtek - The Mic on a RedmiBook doesn't work

The Mic connects to the Nid 0x19, but the configuration of Nid 0x19
is not defined to Mic, and also need to set the coeff to enable the
auto detection on the Nid 0x19. After this change, the Mic plugging
in or plugging out could be detected and could record the sound from
the Mic.

And the coeff value is suggested by Kailang of Realtek.

Cc: Kailang Yang <kailang@realtek.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Hui Wang <hui.wang@canonical.com>
Link: https://lore.kernel.org/r/20200909020041.8967-1-hui.wang@canonical.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>