ARM: dts: omap5: added dt properties to adapt to the new phy framwork

Added device tree bindings for dwc3, usb2 and usb3 PHYs. The documentation
of these can be found at Documentation/devicetree/bindings/phy/phy-bindings.txt
and Documentation/devicetree/bindings/phy/ti-phy.txt.

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