ARM: dts: omap4: update omap-control-usb nodes

Split otghs_ctrl and USB2 PHY power-down into separate
omap-control-usb nodes. Get rid of "ti,type" property.

Also get rid of "ti,has-mailbox" property from usb_otg_hs
node and provide the ctrl-module phandle.

CC: Benoit Cousson <bcousson@baylibre.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>