Add LED lightbar controls for the Dualshock 4.

The Dualshock 4 light bar has 3 separate RGB LEDs that can range in
brightness from 0 to 255 so a full byte is now needed to store each LED's
state

Changed the module to support an arbitrary number of LEDs instead of being
hardcoded to 4.
Signed-off-by: Frank Praznik <frank.praznik@oh.rr.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>