ARM: kirkwood: remove LaCie boards that are supported through DT

The "LaCie Internet Space v2 NAS Board", "LaCie Network Space Max v2
NAS Board" and "LaCie Network Space v2 NAS Board" boards are all
supported through the Device Tree.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>