dt-bindings: usb: dwc3: Add SM8550 compatible

Document the SM8550 dwc3 compatible.

Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221116150600.3011160-1-abel.vesa@linaro.org


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