arm: omap: craneboard: Add USB EHCI support

AM3517/05 Craneboard has one EHCI interface on board using port1.

GPIO35 is used as power enable.
GPIO38 is used as port1 PHY reset.

History:
http://marc.info/?l=linux-omap&w=2&r=1&s=Craneboard%253A%2BAdd%2BUSB%2BEHCI%2Bsupport&q=b



Signed-off-by: Srinath <srinath@mistralsolutions.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>