mtd: nand/docg4: fix driver after Linux resync

Commit dfe64e2c:

    mtd: resync with Linux-3.7.1

broke the docg4 driver.  Specifically:
 - some of the prototypes of the ecc methods changed
 - the NAND_NO_AUTOINCR flag was removed
 - the ecc.strength element was added.

This patch fixes these.  Tested on the docg4 on my palmtre680 board.

Signed-off-by: Mike Dunn <mikedunn@newsguy.com>