Add USB superspeed qmp phy node to dtsi.

Make sure that the various board dts files (which include sm4250.dtsi file)
continue to work as intended.
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230516150511.2346357-4-bhupesh.sharma@linaro.org