usb: phy: Add snapshot of QUSB-V2 PHY driver

This change adds QUSB-V2 driver capabilities on
MSM platforms.This snapshot was taken as of msm-4.14
commit <cd3fb8ae2f0d> ("usb: phy: qusb2: Add regulator
support which powers refgen").

Change-Id: I2620e8d3e45ad9b0d5d63b4d246f120ce85474df
Signed-off-by: Sriharsha Allenki <sallenki@codeaurora.org>