mtd: nand: fsl_ifc: Fix eccstat array overflow for IFC ver >= 2.0.0

mtd: nand: fsl_ifc: Fix eccstat array overflow for IFC ver >= 2.0.0

Number of ECC status registers i.e. (ECCSTATx) has been increased in
IFC version 2.0.0 due to increase in SRAM size. This is causing
eccstat array to over flow.

So, replace eccstat array with u32 variable to make it fail-safe and
independent of number of ECC status registers or SRAM size.

Signed-off-by: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com>
Signed-off-by: Jagdish Gediya <jagdish.gediya@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>