Remove check of ecc bytes with 13, number of errors can directly update
from nand ecc strength. This will increase re-usability of the code.
Also add macro definitions BCH8_ERROR_MAX & BCH4_ERROR_MAX for better
readability and cleaner code.
Signed-off-by: Philip Avinash <avinashphilip@ti.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>