ARM: dts: omap4-panda: Add USB Host support

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

Also provide pin multiplexer information for the USB host
pins.

HACK: The reset control need to be replaced with the proper
gpio-controlled reset driver as soon it will be merged [1].
[1] http://thread.gmane.org/gmane.linux.drivers.devicetree/36830

Signed-off-by: Roger Quadros <rogerq@ti.com>
[benoit.cousson@linaro.org: Add disclaimer about the reset control
inside changelog and code]
Cc: Florian Vaussard <florian.vaussard@epfl.ch>
Signed-off-by: Benoit Cousson <benoit.cousson@linaro.org>