usb: gadget: autoconf: net2280: match hardware and usb ep address

USB3380 GPEP can be used in IN and OUT directions however, both
directions should use same endpoint address. Fulfil this requirement
by mapping usb endpoint to hardware endpoint with the same address.

Tested-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>