nand: arasan_nfc: Clear ecc on bit while sending read command

Clear ecc ON bit while sending read command as all types
of read command(like reading spare) doesnt need ECC to be
enabled. It has been anyway taken care in other places
whereever required using arasan_nand_enable_ecc().

Signed-off-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>