leds: leds-lp55xx: Generalize load_engine function

LED driver based on lp55xx have all a very similar implementation for
load_engine function. Move the function to lp55xx-common and rework the
define to be more dynamic instead of having to declare a temp array for
them.

Engine mask are the same for every LED based on lp55xx.

Suggested-by: Lee Jones <lee@kernel.org>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Link: https://lore.kernel.org/r/20240626160027.19703-6-ansuelsmth@gmail.com


Signed-off-by: Lee Jones <lee@kernel.org>