ARM: OMAP3: MUSB initialization for omap hw, v2

Create a generic board-file for initializing usb
on omap2430 and omap3 boards.

Patch modified by Tony to build the module based on
CONFIG_USB_MUSB_SOC. Also merged in a patch adding
the nop xceiv from Ajay Kumar Gupta <ajay.gupta@ti.com>.

Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>