The DualSense controller has a built-in microphone exposed as an
audio device over USB (or HID using Bluetooth). A dedicated
button on the controller handles mute, but software has to configure
the device to mute the audio stream.

This patch captures the mute button and schedules an output report
to mute/unmute the audio stream as well as toggle the mute LED.
Signed-off-by: Roderick Colenbrander <roderick.colenbrander@sony.com>
Reviewed-by: Barnabás Pőcze <pobrn@protonmail.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>