It is reported that there's a constant background "hum/whitenoise"
in the headset on the Lenovo X1 machines with the codec alc285, and it
is confirmed that if we run the command below, the noise will stop.
 sudo hda-verb /dev/snd/hwC0D0 0x1d SET_PIN_WIDGET_CONTROL 0x0

Then I consulted this issue with Kailang, he told me the pin 0x1d on
this codec is used for PC beep in, the noise probably comes from this
pin and we can also disable the PC beep in passthrough, then the PC
beep in will not affect other sound playback.

Fixes: c4cfcf6f ("ALSA: hda/realtek - fix the pop noise on headphone for lenovo laptops")
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1660581
Cc: <stable@vger.kernel.org>
Signed-off-by: Kailang Yang <kailang@realtek.com>
Signed-off-by: Hui Wang <hui.wang@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>