ARM: dts: omap3-beagle: Add USB Host support

Provide RESET and Power regulators for the USB PHY,
the USB Host port mode and the PHY device.

Also provide pin multiplexer information for USB host
pins.

CC: Benoît Cousson <b-cousson@ti.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>