dt-bindings: usb: add rk3568 compatible to rockchip, dwc3

Add the compatible for the Rockchip RK3568 variant.

Tested-by: Michael Riesch <michael.riesch@wolfvision.net>
Signed-off-by: Michael Riesch <michael.riesch@wolfvision.net>
Link: https://lore.kernel.org/r/20220228135700.1089526-4-pgwipeout@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/usb/rockchip,dwc3.yaml

@@ -30,6 +30,7 @@ select:
         enum:
           - rockchip,rk3328-dwc3
           - rockchip,rk3399-dwc3
+          - rockchip,rk3568-dwc3
   required:
     - compatible
 
@@ -39,6 +40,7 @@ properties:
       - enum:
           - rockchip,rk3328-dwc3
           - rockchip,rk3399-dwc3
+          - rockchip,rk3568-dwc3
       - const: snps,dwc3
 
   reg: