driver/nand:Define MAX_BANKS same as SoC defined for IFC

The number of chip select used by IFC controller vary from one SoC to other.
For eg. P1010 has 4, T4240 has 8.

Update MAX_BANKS same as SoC defined

Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
1 file changed