dt-bindings: power: rockchip: Add bindings for RK3568 Soc

Add the compatible string for RK3568 SoC.
Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210417112952.8516-15-jbx6244@gmail.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>

Documentation/devicetree/bindings/power/rockchip,power-controller.yaml

@@ -40,6 +40,7 @@ properties:
       - rockchip,rk3366-power-controller
       - rockchip,rk3368-power-controller
       - rockchip,rk3399-power-controller
+      - rockchip,rk3568-power-controller
 
   "#power-domain-cells":
     const: 1
@@ -117,6 +118,7 @@ $defs:
           "include/dt-bindings/power/rk3366-power.h"
           "include/dt-bindings/power/rk3368-power.h"
           "include/dt-bindings/power/rk3399-power.h"
+          "include/dt-bindings/power/rk3568-power.h"
 
       clocks:
         minItems: 1