dt-bindings: usb: dwc3: add sdm670 compatible

The Snapdragon 670 has DWC3 USB support. Add a compatible to reflect
that.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Richard Acayan <mailingradian@gmail.com>
Link: https://lore.kernel.org/r/20220922024656.178529-3-mailingradian@gmail.com


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