mtd: rawnand: fix a kernel-doc markup

Some identifiers have different names between their prototypes
and the kernel-doc markup.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/9ed47a57d12c40e73a9b01612ee119d39baa6236.1603469755.git.mchehab+huawei@kernel.org