dt-bindings: power: rockchip: Document RV1126 power-controller

Document dt-bindings for RV1126 power-controller.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Jagan Teki <jagan@edgeble.ai>
Link: https://lore.kernel.org/r/20220818124132.125304-3-jagan@edgeble.ai


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