dt-bindings: usb: dwc3-xilinx: add optional property reset-gpios

Added optional property support reset-gpios for the dwc3-Xilinx
glue driver.
Signed-off-by: Piyush Mehta <piyush.mehta@xilinx.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220504075309.6244-2-piyush.mehta@xilinx.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/usb/dwc3-xilinx.yaml

@@ -71,6 +71,10 @@ properties:
         - usb2-phy
         - usb3-phy
 
+  reset-gpios:
+    description: GPIO used for the reset ulpi-phy
+    maxItems: 1
+
 # Required child node:
 
 patternProperties: