usb: gadget: USB_NET2272_DMA should depend on HAS_DMA

If NO_DMA=y:

drivers/built-in.o: In function `net2272_done':
drivers/usb/gadget/net2272.c:386: undefined reference to `usb_gadget_unmap_request'
drivers/built-in.o: In function `net2272_queue':
drivers/usb/gadget/net2272.c:848: undefined reference to `usb_gadget_map_request'

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>