mtd: onenand: Fix some kernel-doc misdemeanours

Fixes the following W=1 kernel build warning(s):

 drivers/mtd/nand/onenand/onenand_base.c:140: warning: Function parameter or member 'mtd' not described in 'onenand_ooblayout_32_64_ecc'
 drivers/mtd/nand/onenand/onenand_base.c:140: warning: Function parameter or member 'section' not described in 'onenand_ooblayout_32_64_ecc'
 drivers/mtd/nand/onenand/onenand_base.c:140: warning: Function parameter or member 'oobregion' not described in 'onenand_ooblayout_32_64_ecc'
 drivers/mtd/nand/onenand/onenand_base.c:1436: warning: bad line:
 drivers/mtd/nand/onenand/onenand_base.c:1971: warning: Function parameter or member 'ops' not described in 'onenand_write_oob_nolock'
 drivers/mtd/nand/onenand/onenand_base.c:1971: warning: Excess function parameter 'len' description in 'onenand_write_oob_nolock'
 drivers/mtd/nand/onenand/onenand_base.c:1971: warning: Excess function parameter 'retlen' description in 'onenand_write_oob_nolock'
 drivers/mtd/nand/onenand/onenand_base.c:1971: warning: Excess function parameter 'buf' description in 'onenand_write_oob_nolock'
 drivers/mtd/nand/onenand/onenand_base.c:1971: warning: Excess function parameter 'mode' description in 'onenand_write_oob_nolock'
 drivers/mtd/nand/onenand/onenand_base.c:2156: warning: Function parameter or member 'block_size' not described in 'onenand_multiblock_erase'
 drivers/mtd/nand/onenand/onenand_base.c:2156: warning: Excess function parameter 'region' description in 'onenand_multiblock_erase'
 drivers/mtd/nand/onenand/onenand_base.c:2771: warning: Function parameter or member 'ops' not described in 'onenand_otp_write_oob_nolock'
 drivers/mtd/nand/onenand/onenand_base.c:2771: warning: Excess function parameter 'len' description in 'onenand_otp_write_oob_nolock'
 drivers/mtd/nand/onenand/onenand_base.c:2771: warning: Excess function parameter 'retlen' description in 'onenand_otp_write_oob_nolock'
 drivers/mtd/nand/onenand/onenand_base.c:2771: warning: Excess function parameter 'buf' description in 'onenand_otp_write_oob_nolock'
 drivers/mtd/nand/onenand/onenand_base.c:3387: warning: Function parameter or member 'mtd' not described in 'flexonenand_get_boundary'
 drivers/mtd/nand/onenand/onenand_base.c:3387: warning: Excess function parameter 'onenand_info' description in 'flexonenand_get_boundary'
 drivers/mtd/nand/onenand/onenand_base.c:3509: warning: Function parameter or member 'mtd' not described in 'flexonenand_check_blocks_erased'
 drivers/mtd/nand/onenand/onenand_base.c:3509: warning: Excess function parameter 'mtd_info' description in 'flexonenand_check_blocks_erased'
 drivers/mtd/nand/onenand/onenand_base.c:3557: warning: Function parameter or member 'die' not described in 'flexonenand_set_boundary'
 drivers/mtd/nand/onenand/onenand_base.c:3557: warning: Function parameter or member 'boundary' not described in 'flexonenand_set_boundary'
 drivers/mtd/nand/onenand/onenand_base.c:3557: warning: Function parameter or member 'lock' not described in 'flexonenand_set_boundary'

Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Cc: linux-mtd@lists.infradead.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20201109182206.3037326-23-lee.jones@linaro.org