mini2440: build usb ether, not working yet

Signed-off-by: Fudong Bai <fudongbai@gmail.com>
mini2440: put off udc init

Signed-off-by: Fudong Bai <fudongbai@gmail.com>
mini2440: udc gadget driver works

Test with usbled gadget

NOTE:
only works when flash u-boot.bin into nand flash, not working when
directly execute from ram, this is probably because the usb device
controller is configured before, we may need do a hard reset to make it
work.

Signed-off-by: Fudong Bai <fudongbai@gmail.com>