Enables NXP/FSL QorIQ IFC flash controller driver for NAND.  Enabled as
built-in to load RFS from nand flash without initramfs.

Remove CONFIG_MEMORY as it is selected by CONFIG_MTD_NAND_FSL_IFC.
Signed-off-by: NLi Yang <leoyang.li@nxp.com>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>