mtd: nand: Fix on-die ecc issues in arasan_nfc driver

Fixed wrong enumeration of nand_config structure. Added chip select
function before reading the nand chip for maf/dev id's, without this
unable to access id's from some of the micron chips. Also added a
print statement to identify if a nand flash is using on-die ecc.

Signed-off-by: T Karthik Reddy <t.karthik.reddy@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>