dt-bindings: soc: rockchip: grf: add rockchip,lvds.yaml

Add new converted rockchip,lvds.yaml to grf.yaml file.
Prepare for more SoCs with lvds output.
Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/ff3644da-e5ae-f795-c7d9-454b8c8bdfe8@gmail.com

Documentation/devicetree/bindings/soc/rockchip/grf.yaml

@@ -75,13 +75,17 @@ allOf:
       properties:
         compatible:
           contains:
-            const: rockchip,px30-grf
+            enum:
+              - rockchip,px30-grf
 
     then:
       properties:
         lvds:
-          description:
-            Documentation/devicetree/bindings/display/rockchip/rockchip-lvds.txt
+          type: object
+
+          $ref: /schemas/display/rockchip/rockchip,lvds.yaml#
+
+          unevaluatedProperties: false
 
   - if:
       properties: