ARM: dts: OMAP4: Add omap control usb data

Add omap control usb data in omap4 device tree file. This will have the
register address of registers to power on the PHY and to write to
mailbox. The information about this data node is available @
Documentation/devicetree/bindings/usb/omap-usb.txt

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Benoit Cousson <benoit.cousson@linaro.org>