leds: qnap-mcu: Add support for the red and green status LEDs

leds: qnap-mcu: Add support for the red and green status LEDs

There is one more set of two LEDs on the qnap devices to indicate status.

One LED is green, the other is red and while they occupy the same space
on the front panel, they cannot be enabled at the same time.

But they can interact via blink functions, the MCU can flash them
alternately, going red -> green -> red -> ... either in 500ms or
1s intervals. They can of course also blink individually.

Add specific LED functions for them and register them on probe.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20250804114949.3127417-3-heiko@sntech.de
Signed-off-by: Lee Jones <lee@kernel.org>