mtd: rawnand: Deprecate ->block_{bad,markbad}() hooks

Those hooks have been overloaded by some drivers for bad reasons:
either the driver was not fitting in the NAND framework and should
have been an MTD driver (docg4), or it was not properly implementing
the OOB read/write request or had a weird layout where BBM are trashed.
In any case, we should discourage people from overloading those
methods and encourage them to fix their driver instead.

Move the ->block_{bad,markbad}() hooks to the nand_legacy struct to
make it clear.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
diff --git a/drivers/mtd/nand/raw/diskonchip.c b/drivers/mtd/nand/raw/diskonchip.c
index c3a7936..16fdfd0 100644
--- a/drivers/mtd/nand/raw/diskonchip.c
+++ b/drivers/mtd/nand/raw/diskonchip.c
@@ -1572,7 +1572,7 @@
 	nand->legacy.cmd_ctrl		= doc200x_hwcontrol;
 	nand->legacy.dev_ready	= doc200x_dev_ready;
 	nand->legacy.waitfunc	= doc200x_wait;
-	nand->block_bad		= doc200x_block_bad;
+	nand->legacy.block_bad	= doc200x_block_bad;
 	nand->ecc.hwctl		= doc200x_enable_hwecc;
 	nand->ecc.calculate	= doc200x_calculate_ecc;
 	nand->ecc.correct	= doc200x_correct_data;