arm64: dts: qcom: msm8992: Add USB support

This is a very basic dwc3 configuration (no PHYs yet),
but it works.

Signed-off-by: Konrad Dybcio <konradybcio@gmail.com>
Link: https://lore.kernel.org/r/20201005150313.149754-11-konradybcio@gmail.com


Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>