fsl_udc_core: add support for devices provided by fsl-mph-dr-of

Currently the of glue code in fsl-mph-dr-of will create the platform
device fsl-usb2-udc. As this driver should also be probed by this name,
this patch adds it to the devtypes list.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>