dt-bindings: usb: qcom,dwc3: Add bindings for SC7280

Add the compatible string for sc7280 SoC from Qualcomm.

Signed-off-by: Sandeep Maheswaram <sanm@codeaurora.org>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Link: https://lore.kernel.org/r/1615978901-4202-2-git-send-email-sanm@codeaurora.org


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