leds: max5970: Add support for max5970

The MAX5970 is hot swap controller and has 4 indication LED.

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
Link: https://lore.kernel.org/r/20231123132803.1107174-1-naresh.solanki@9elements.com


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