dt-bindings: usb: ci-hdrc-usb2: add fsl,imx8ulp-usb compatible

The imx8ulp and imx8dxl are compatible. This will add fsl,imx8ulp-usb
to the compatible property.

Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Message-ID: <20230530104007.1294702-1-xu.yang_2@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>