mtd: devices: docg3: Fix kernel-doc 'bad line' and 'excessive doc' issues

This patch also places the descriptions in the correct order.

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

 drivers/mtd/devices/docg3.c:819: warning: bad line:
 drivers/mtd/devices/docg3.c:1799: warning: Excess function parameter 'base' description in 'doc_probe_device'

Cc: Robert Jarzmik <robert.jarzmik@free.fr>
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/20201109182206.3037326-5-lee.jones@linaro.org