uboot-imx

sunxi: automatically select SPL_NAND_SUPPORT in Kconfig

Make SUNXI_NAND select SPL_NAND_SUPPORT in Kconfig, this limit the
number of entries to add in defconfig files when adding NAND support.

For now, the only board using it is the CHIP pro.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>