dt-bindings: usb: mtu3: add compatible for mt8188

Add a new compatible for mt8188
Acked-by: NKrzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: NChunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/20220819081027.32382-1-chunfeng.yun@mediatek.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/usb/mediatek,mtu3.yaml

@@ -24,6 +24,7 @@ properties:
           - mediatek,mt2712-mtu3
           - mediatek,mt8173-mtu3
           - mediatek,mt8183-mtu3
+          - mediatek,mt8188-mtu3
           - mediatek,mt8192-mtu3
           - mediatek,mt8195-mtu3
       - const: mediatek,mtu3