Enable ONFI detection to fix NAND chip configuration. Without this
the NAND oobsize will be wrong which leads to invalid ECC strength and
incompatibility with the previous configuration.

Fixes: 777f333c ("imx: ventana: enable dm for MTD and NAND")

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Reviewed-by: Fabio Estevam <festevam@denx.de>