Armadillo 500 add NAND flash device support (resend).

Since recent mxc_nand driver fixes from linux-mtd this patch
add support for ST NAND02GW3B2CN6 (2k pages flash) placed on the armadillo 500
motherboard.

Signed-off-by: Alberto Panizzo <maramaopercheseimorto@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>