ALSA: hda/realtek: Fix hiss/crackle on Lenovo Xiaoxin 14 GT (17aa:3912)

Commit 3a3e810e9108 ("ALSA: hda/realtek: Add quirk for Lenovo Xiaoxin
14 GT") added a quirk mapping SSID 17aa:3912 to
ALC287_FIXUP_YOGA9_14IAP7_BASS_SPK_PIN, chosen by analogy with
neighboring SSIDs (0x390d, 0x3911, 0x391a) without being verified on
hardware, as noted in that commit's own message.

I have since tested it on the actual hardware (Lenovo Xiaoxin Pro 14
ASP10, same 17aa:3912 SSID) and confirmed it does not fix the reported
issue. ALC287_FIXUP_YOGA9_14IAP7_BASS_SPK_PIN only repoints pin 0x17
and the preferred DAC pairs for the bass speaker; it does not touch
the codec's vendor processing coefficients. The actual symptom -
constant electrical hiss/crackle on both the headphone jack and the
internal speakers, independent of volume - is unrelated to pin/DAC
routing and is also present on stock Windows before the Realtek
driver is installed, which points at those coefficients being left
at their power-on default.

To find the correct values, I passed the physical HD Audio controller
through to a Windows 10 VM (VFIO, with QEMU patched to log CORB verb
traffic) and captured the coefficient writes the vendor Realtek driver
performs at init. Replaying a single one of them on Linux via hda-verb
reproducibly eliminates the headphone jack noise:

    hda-verb /dev/snd/hwC#D0 0x20 SET_COEF_INDEX 0x36
    hda-verb /dev/snd/hwC#D0 0x20 SET_PROC_COEF  0x77d7

This has held up across reboots and kernel updates for several weeks
(applied via a small systemd oneshot unit while testing).

Add a dedicated fixup that performs this coefficient write and chains
it with the existing ALC287_FIXUP_YOGA9_14IAP7_BASS_SPK_PIN (which may
still be relevant for the bass speaker pin wiring on this board), and
point the 17aa:3912 quirk entry at it instead.

Honesty note: this fixes the headphone jack. The internal speakers
still have noise under certain conditions (notably worse on AC power)
that I have not been able to isolate via coefficient-table replay;
that part remains open. Sending what is verified to work rather than
holding this back.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=221203
Fixes: 3a3e810e9108 ("ALSA: hda/realtek: Add quirk for Lenovo Xiaoxin 14 GT")
Signed-off-by: Viktor Menshin <ripeeerr@gmail.com>
Link: https://patch.msgid.link/20261015132157.57198-1-ripeeerr@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

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