nand: Freescale Integrated Flash Controller NAND support

Add NAND support (including spl) on IFC, such as is found on the p1010.

Note that using hardware ECC on IFC with small-page NAND (which is what
comes on the p1010rdb reference board) means there will be insufficient
OOB space for JFFS2, since IFC does not support 1-bit ECC.  UBI should
work, as it does not use OOB for anything but ECC.

When hardware ECC is not enabled in CSOR, software ECC is now used.

Signed-off-by: Dipen Dudhat <Dipen.Dudhat@freescale.com>
[scottwood@freescale.com: ECC rework and misc fixes]
Signed-off-by: Scott Wood <scottwood@freescale.com>