usb: phy: Add snapshot of PHY msm usb driver

This change adds PHY msm usb driver which handles PHY
initialization, clock management, and workarounds
required after resetting the hardware and power management.

This snapshot is taken as of msm-3.18 'commit 4a06b0168aeb ("ANDROID:
sdcardfs: Make WARN_RATELIMIT to pr_debug")'.

This change also preserves the structure and API design
changes present on 4.9 kernel; along with fixing the
coding style errors.

Change-Id: Icbec28f109becce1a2d7693d4cab0919008621b8
Signed-off-by: Ajay Agarwal <ajaya@codeaurora.org>