ARM: dts: omap5: Add clocks to USB3 PHY node

The USB3 PHY driver (ti-pipe3) was updated so that the relevant
clock phandles are expected in the DT node.
Provide the necessary clocks.

Reported-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>