drivers: phy: usb3/pipe3: Adapt pipe3 driver to Generic PHY Framework

Adapted omap-usb3 PHY driver to Generic PHY Framework and moved phy-omap-usb3
driver in drivers/usb/phy to drivers/phy and also renamed the file to
phy-ti-pipe3 since this same driver will be used for SATA PHY and
PCIE PHY.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>