Add ChromeOS EC-based LED control as EC subdevice.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20240613-cros_ec-led-v3-5-500b50f41e0f@weissschuh.netSigned-off-by: Lee Jones <lee@kernel.org>