UPSTREAM: usb: phy: msm: Remove HSUSB prefix from regulator names

Prefix did not bring any useful information. Currently none
of the MSM platforms define these regulators, so it is safe
to rename them.

Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>