dt-bindings: connector: add optional properties for Type-B

Add id-gpios, vbus-gpios, vbus-supply and pinctrl properties for
usb-b-connector

Signed-off-by: Chunfeng Yun <[e-mail]>
Reviewed-by: Rob Herring <[e-mail]>
Reviewed-by: Linus Walleij <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/devicetree/bindings/connector/usb-connector.txt

···
 - self-powered: Set this property if the usb device that has its own power
   source.
 
+Optional properties for usb-b-connector:
+- id-gpios: an input gpio for USB ID pin.
+- vbus-gpios: an input gpio for USB VBUS pin, used to detect presence of
+  VBUS 5V.
+  see gpio/gpio.txt.
+- vbus-supply: a phandle to the regulator for USB VBUS if needed when host
+  mode or dual role mode is supported.
+  Particularly, if use an output GPIO to control a VBUS regulator, should
+  model it as a regulator.
+  see regulator/fixed-regulator.yaml
+- pinctrl-names : a pinctrl state named "default" is optional
+- pinctrl-0 : pin control group
+  see pinctrl/pinctrl-bindings.txt
+
 Optional properties for usb-c-connector:
 - power-role: should be one of "source", "sink" or "dual"(DRP) if typec
   connector has power support.