mtd: atmel_nand: pmecc: fix bug fail to correct bit error in 1024-bytes sector
The PMECC use BCH algorithm to correct error. In BCH algorithm, the
primitive polynomial value is GF(2^13) for 512-bytes sector size. And it is
GF(2^14) for 1024-bytes sector size.
This patch will choose correct degree of the remainders (13 or 14) for
different sector size.
Tested in AT91SAM9X5-EK with MLC nand flash.
More detail can be refered to section 5.4.1 of:
AT91SAM ARM-based Embedded MPU Application Note
<http://www.atmel.com/Images/doc11127.pdf>
Signed-off-by: Josh Wu <josh.wu@atmel.com> Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>