dt-bindings: usb: add hisilicon,hi3798mv200-dwc3

Document the DWC3 controller used by Hi3798MV200.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Yang Xiwen <forbidden405@outlook.com>
Link: https://lore.kernel.org/r/20240225-dwc3-v4-1-8c1fd6c6f615@outlook.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>