dt-bindings: usb: qcom,dwc3: allow required-opps

dt-bindings: usb: qcom,dwc3: allow required-opps

Few Qualcomm SoCs require minimum performance level of power domain, so
allow it:

  sm8550-mtp.dtb: usb@a6f8800: 'required-opps' does not match any of the regexes: '^usb@[0-9a-f]+$', 'pinctrl-[0-9]+'

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Abel Vesa <abel.vesa@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230127121122.342191-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>