arm64: dts: rockchip: Adapt to differences between Orange Pi 5 Max and Ultra

arm64: dts: rockchip: Adapt to differences between Orange Pi 5 Max and Ultra

The Orange Pi 5 Plus and Orange Pi 5 Max have 2SK3018s attached to the
PWM LEDs. The Orange Pi 5 Ultra does not, and thus needs the PWM
polarity inverted.

Also remove the model/compatible from the dtsi. It should be at the
board level only.

Fixes: c600d252dc52 ("arm64: dts: rockchip: Add Orange Pi 5 Max board")
Signed-off-by: Jimmy Hon <honyuenkwun@gmail.com>
Link: https://lore.kernel.org/r/20250222193332.1761-2-honyuenkwun@gmail.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>