ARM: mvebu: remove static LED setup for netxbig boards

Since DT support is now available for the LEDs found on the LaCie
netxbig boards (Kirkwood-based), then the old-fashion netxbig board
setup file is no longer needed. This patch removes this file.

Signed-off-by: Simon Guinot <simon.guinot@sequanux.org>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>