[MTD] [NAND] S3C2410: NAND ECC by chip rather than global

This makes us take note about the chosen ECC mode per-chip and
not the one set globally.

Signed-off-by: Andy Green <andy@warmcat.com>
Signed-off-by: Nelson Castillo <arhuaco@freaks-unidos.net>
[ben-linux@fluff.org: andy@openmoko.com => andy@warmcat.com, rewrite subject]
Signed-off-by: Ben Dooks <ben-linux@fluff.org>