mtd: fsmc_nand: ECC1 & ECC4 layout separated for different page sizes

ECC1 & ECC4 layout for NAND of different pages sizes for e.g. 512bytes,
2KiB, 4KiB and 8KiB are separated. Previously there existed one ECC4
layout for 2KiB & 4KiB page size due to which oob test module available
in drivers/mtd/nand/test was failing.

Signed-off-by: Bhavna Yadav <bhavna.yadav@st.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>