usb: gadget: udc: net2280: Remove obsolete module param use_dma_chaining

use_dma_chaining module parameter was designed to avoid creating one irq
per package on a group of packages (with the help of the driver's flag
no_interrupt).

Unfortunately, when this parameter is enabled, the driver fails to work
on both net2280 and 3380 chips.

This patch removes this parameter, which was disabled by default.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>