dt-bindings: usb: add DT binding for s3c2410 USB OHCI controller

Adds the device tree bindings description for Samsung S3C2410 and
compatible USB OHCI controller.

Signed-off-by: Sergio Prado <sergio.prado@e-labworks.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>