arm64: dts: rockchip: add status LED to rock-5b

Describe the Rock 5B status LED in its device tree.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/20231005134037.33231-1-sebastian.reichel@collabora.com


Signed-off-by: Heiko Stuebner <heiko@sntech.de>