dt-bindings: usb: Use OF graph schema

Now that we have a graph schema, rework the USB related schemas to use
it. Mostly this is adding a reference to graph.yaml and dropping duplicate
parts from schemas.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: Biju Das <biju.das.jz@bp.renesas.com>
Cc: linux-usb@vger.kernel.org
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20210112153527.391232-1-robh@kernel.orgSigned-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/usb/renesas,usb3-peri.yaml

@@ -54,18 +54,19 @@ properties:
     description: phandle of a companion.
 
   ports:
+    $ref: /schemas/graph.yaml#/properties/ports
     description: |
       any connector to the data bus of this controller should be modelled
       using the OF graph bindings specified, if the "usb-role-switch"
       property is used.
-    type: object
+
     properties:
       port@0:
-        type: object
+        $ref: /schemas/graph.yaml#/properties/port
         description: High Speed (HS) data bus.
 
       port@1:
-        type: object
+        $ref: /schemas/graph.yaml#/properties/port
         description: Super Speed (SS) data bus.
 
     required:

Documentation/devicetree/bindings/usb/ti,hd3ss3220.yaml

@@ -26,17 +26,17 @@ properties:
     maxItems: 1
 
   ports:
+    $ref: /schemas/graph.yaml#/properties/ports
     description: OF graph bindings (specified in bindings/graph.txt) that model
       SS data bus to the SS capable connector.
-    type: object
+
     properties:
       port@0:
-        type: object
+        $ref: /schemas/graph.yaml#/properties/port
         description: Super Speed (SS) MUX inputs connected to SS capable connector.
-        $ref: /connector/usb-connector.yaml#/properties/ports/properties/port@1
 
       port@1:
-        type: object
+        $ref: /schemas/graph.yaml#/properties/port
         description: Output of 2:1 MUX connected to Super Speed (SS) data bus.
 
     required: