phy: qcom: add Qualcomm QUSB2 USB PHY driver

phy: qcom: add Qualcomm QUSB2 USB PHY driver

The Snapdragon 845 and several other Qualcomm SoCs feature this
USB high-speed phy. Add a driver for it based on the Linux driver, with
support for the SDM845, and the QCM2290 and SM6115 SoCs which will gain
support in U-Boot in future patches.

Signed-off-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
[code cleanup, switch to clk_bulk]
Acked-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>