mtd: onenand: switch to mtd_ooblayout_ops

Implementing the mtd_ooblayout_ops interface is the new way of exposing
ECC/OOB layout to MTD users. Modify the onenand drivers to switch to this
approach.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

include/linux/mtd/onenand.h

@@ -80,7 +80,6 @@ struct onenand_bufferram {
  * @page_buf:		[INTERN] page main data buffer
  * @oob_buf:		[INTERN] page oob data buffer
  * @subpagesize:	[INTERN] holds the subpagesize
- * @ecclayout:		[REPLACEABLE] the default ecc placement scheme
  * @bbm:		[REPLACEABLE] pointer to Bad Block Management
  * @priv:		[OPTIONAL] pointer to private chip date
  */
@@ -134,7 +133,6 @@ struct onenand_chip {
 #endif
 
 	int			subpagesize;
-	struct nand_ecclayout	*ecclayout;
 
 	void			*bbm;