HID: lenovo: Set default_triggers for the mute and micmute LEDs

The mute and mic-mute LEDs should be automatically turned on/off based
on the audio-card's mixer settings.

Add the standardized default-trigger names for this, so that the alsa
code can turn the LEDs on/off as appropriate (on supported audio cards).

This brings the mute/mic-mute LED support inline with the thinkpad_acpi
support for the same LEDs in keyboards directly connected to the
laptop's embedded-controller.

Reviewed-by: Marek Behún <kabel@kernel.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>