Till the OMAP clocks are correctly defined in device tree, use
this temporary hack to provide clock alias to the USB PHY clocks.

Without this, USB Host & Ethernet will not be functional with
device tree boots on Panda and uEVM.
Signed-off-by: NRoger Quadros <rogerq@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>