usb: mv_udc: Unbreak the mv_udc driver

The mv_udc driver is broken for a while and doesn't even compile.
This patch fixes the issues and gets the driver into working state
again. This driver was tested on Freescale i.MX233/i.MX28 .

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Lei Wen <leiwen@marvell.com>
Cc: Otavio Salvador <otavio@ossystems.com.br>
Cc: Stefano Babic <sbabic@denx.de>