mtd: fix nand kernel-doc warnings

Warning(include/linux/mtd/nand.h:543): No description found for parameter 'badblockbits'
Warning(drivers/mtd/nand/nand_bbt.c:1101): No description found for parameter 'mtd'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc:	David Woodhouse <dwmw2@infradead.org>
Cc:	linux-mtd@lists.infradead.org
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c
index 586b981..6ebd869 100644
--- a/drivers/mtd/nand/nand_bbt.c
+++ b/drivers/mtd/nand/nand_bbt.c
@@ -1092,7 +1092,8 @@
 
 /**
  * verify_bbt_descr - verify the bad block description
- * @bd:			the table to verify
+ * @mtd:	MTD device structure
+ * @bd:		the table to verify
  *
  * This functions performs a few sanity checks on the bad block description
  * table.
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 63e17d0..1f489b2 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -448,6 +448,8 @@
  *			See the defines for further explanation.
  * @badblockpos:	[INTERN] position of the bad block marker in the oob
  *			area.
+ * @badblockbits:	[INTERN] number of bits to left-shift the bad block
+ *			number
  * @cellinfo:		[INTERN] MLC/multichip data from chip ident
  * @numchips:		[INTERN] number of physical chips
  * @chipsize:		[INTERN] the size of one chip for multichip arrays