mtd: nand: Fix a docs build warning

Commit 0b4773fd (mtd: nand: Drop unused cached programming support)
removed the "cached" parameter from nand_write_page(), but did not update
the kerneldoc comments, creating this docs build warning:

  ./drivers/mtd/nand/nand_base.c:2751: warning: Excess function parameter 'cached' description in 'nand_write_page'

Remove the offending line so we can have a little peace and quiet.
Signed-off-by: NJonathan Corbet <corbet@lwn.net>
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

drivers/mtd/nand/nand_base.c

@@ -2747,7 +2747,6 @@ static int nand_write_page_syndrome(struct mtd_info *mtd,
  * @buf: the data to write
  * @oob_required: must write chip->oob_poi to OOB
  * @page: page number to write
- * @cached: cached programming
  * @raw: use _raw version of write_page
  */
 static int nand_write_page(struct mtd_info *mtd, struct nand_chip *chip,