ALSA: hda/realtek: Fixes HP Spectre x360 15-eb1xxx speakers

ALSA: hda/realtek: Fixes HP Spectre x360 15-eb1xxx speakers

In laptop 'HP Spectre x360 Convertible 15-eb1xxx/8811' both front and
rear speakers are silent, this patch fixes that by overriding the pin
layout and by initializing the amplifier which needs a GPIO pin to be
set to 1 then 0, similar to the existing HP Spectre x360 14 model.

In order to have volume control, both front and rear speakers were
forced to use the DAC1.

This patch also correctly map the mute LED but since there is no
microphone on/off switch exposed by the alsa subsystem it never turns
on by itself.

There are still known audio issues in this laptop: headset microphone
doesn't work, the button to mute/unmute microphone is not yet mapped,
the LED of the mute/unmute speakers doesn't seems to be exposed via
GPIO and never turns on.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=213953
Signed-off-by: Davide Baldo <davide@baldo.me>
Link: https://lore.kernel.org/r/20211015072121.5287-1-davide@baldo.me
Signed-off-by: Takashi Iwai <tiwai@suse.de>