Adds support for usages that may appear on the pen or pad interface which
report the state of the tablet battery.
Signed-off-by: NJason Gerecke <jason.gerecke@wacom.com>
Reviewed-by: NBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>