leds: Add NCP5623 multi-led driver

NCP5623 is DC-DC multi-LEDs driver which has three PWMs that can be
programmed up to 32 steps giving 32768 colors hue.

NCP5623 driver supports gradual dimming upward/downward with programmable
delays. Also, the driver supports driving a single LED or multi-LED
like RGB.

Signed-off-by: Abdel Alkuor <alkuor@gmail.com>
Link: https://lore.kernel.org/r/20240305042049.1533279-2-alkuor@gmail.com


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