usb: dwc2: gadget: Set GDFIFOCFG

Add programming of GDFIFOCFG register in device mode.
It must contain start address for EP Info block and
total FIFO depth.

Signed-off-by: Sevak Arakelyan <sevaka@synopsys.com>
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>