dt-bindings: usb: mtu3: add compatible for mt8186

Add a new compatible for mt8186 SoC.

Signed-off-by: Allen-KH Cheng <allen-kh.cheng@mediatek.com>
Link: https://lore.kernel.org/r/20221123135531.23221-2-allen-kh.cheng@mediatek.com


Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>