uboot-imx

mx28evk: add NAND support

NAND support is not enabled by default because Eval Kit is not delivered
with NAND chip. To enable NAND support add CONFIG_CMD_NAND to board config.

Signed-off-by: Lauri Hintsala <lauri.hintsala@bluegiga.com>
Acked-by: Marek Vasut <marex@denx.de>