dt-bindings: phy: add vbus-supply optional property to phy-stm32-usbphyc

This patch adds vbus-supply optional property to phy sub-nodes using
connector node.
A regulator for USB VBUS may be needed for host mode.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Link: https://lore.kernel.org/r/20210517120821.26466-2-amelie.delaunay@foss.st.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml

@@ -74,6 +74,13 @@ patternProperties:
       "#phy-cells":
         enum: [ 0x0, 0x1 ]
 
+      connector:
+        type: object
+        allOf:
+          - $ref: ../connector/usb-connector.yaml
+        properties:
+          vbus-supply: true
+
     allOf:
       - if:
           properties:
@@ -130,6 +137,10 @@ examples:
             reg = <0>;
             phy-supply = <&vdd_usb>;
             #phy-cells = <0>;
+            connector {
+                compatible = "usb-a-connector";
+                vbus-supply = <&vbus_sw>;
+            };
         };
 
         usbphyc_port1: usb-phy@1 {