leds: Drop BUG_ON check for LED_COLOR_ID_MULTI

[ Upstream commit 9dc1664f ]

Commit c3f85318 ("leds: Fix BUG_ON check for LED_COLOR_ID_MULTI that
is always false") fixed a no-op BUG_ON. This turned out to cause a
regression, since some in-tree device-tree files already use
LED_COLOR_ID_MULTI.

Drop the BUG_ON altogether.

Fixes: c3f85318

 ("leds: Fix BUG_ON check for LED_COLOR_ID_MULTI that is always false")
Reported-by: Da Xue <da@libre.computer>
Closes: https://lore.kernel.org/linux-leds/ZQLelWcNjjp2xndY@duo.ucw.cz/T/
Signed-off-by: Marek Behún <kabel@kernel.org>
Link: https://lore.kernel.org/r/20230918140724.18634-1-kabel@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>