arm: kirkwood: enable DM_USB for LaCie board

This patch enables DM_USB and USB_STORAGE for the following
Kirkwood-based LaCie boards:

- d2 Network v2
- Internet Space v2
- 2Big Network v2
- Network Space v2
- Network Space Lite v2
- Network Space Max v2

Signed-off-by: Simon Guinot <simon.guinot@sequanux.org>
Reviewed-by: Stefan Roese <sr@denx.de>