mvebu: add large NOR sub-profile implementation

While we supported only the NAND so far, some boards use a large enough NOR,
where UBI is the only reasonable option. Create a new sub-profile template with
a different set of UBI options.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Imre Kaloz <kaloz@openwrt.org>

SVN-Revision: 44262