leds: turris-omnia: Use command execution functions from the MCU driver

Use the MCU command execution functions from the MCU driver instead of
the ad-hoc implementation in the LED driver. This allows as to drop the
LED driver implementation, which is a duplicate.

Signed-off-by: Marek Behún <kabel@kernel.org>
Link: https://lore.kernel.org/r/20241111100355.6978-3-kabel@kernel.org


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