ARM: OMAP2+: omap4panda: Adapt to ehci-omap changes

Use usbhs_init_phys() to register the PHY's VCC and RESET
regulators and the NOP PHY device.

Get rid of managing the PHY clock as it will be done by the PHY driver.
For that to work we create a clock alias that links the PHY clock name
to the PHY device name.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>