usb: chipidea: add support for USB OTG controller on LSI Zevio SoCs

The USB controller in TI-NSPIRE calculators (LSI Zevio SoC) are based off either
Freescale's USB OTG controller or the USB controller found in the IMX233, both
of which are Chipidea compatible.

This patch adds a device tree binding for the controller.

Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Daniel Tang <dt.tangr@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>