ALSA: hda/realtek: Add mute LED fixup for HP Pavilion 15-cs1xxx

ALSA: hda/realtek: Add mute LED fixup for HP Pavilion 15-cs1xxx

Add a new fixup for the mute LED on the HP Pavilion 15-cs1xxx series
using the VREF on NID 0x1b.

The BIOS on these models (tested up to F.32) incorrectly reports
the mute LED on NID 0x18 via DMI OEM strings, which lacks VREF
capabilities. This fixup overrides the LED pin to the correct
NID 0x1b.

Signed-off-by: Rodrigo Faria <rodrigofilipefaria@gmail.com>
Link: https://patch.msgid.link/20260505185518.23625-1-rodrigofilipefaria@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>