ALSA: hda: cs35l41: Add read-only ALSA control for forced mute

When the CS35L41 amp is requested to mute using the ACPI
notification mechanism, userspace is not notified that the amp
is muted. To allow userspace to know about the mute, add an
ALSA control which tracks the forced mute override.
This control does not track the overall mute state of the amp,
since the amp is only unmuted during playback anyway, instead
it tracks the mute override request from the ACPI notification.

Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230921162849.1988124-5-sbinding@opensource.cirrus.com


Signed-off-by: Takashi Iwai <tiwai@suse.de>