dt-bindings: usb: mtk-xhci: Allow wakeup interrupt-names to be optional

Add missing "minItems: 1" to the interrupt-names property to allow the
second interrupt-names, "wakeup", to be optional.

Fixes: fe8e4880 ("dt-bindings: usb: mtk-xhci: add wakeup interrupt")
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/20220623193702.817996-2-nfraprado@collabora.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>