It is preferred to have the documentation about the drivers directly
embedded in the driver itself. Remove this file now that the most
important information from this file have been re-written in
marvell_nand.c.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Boris Brezillon <boris.brezillon@bootlin.com>
Acked-by: Ezequiel Garcia <ezequiel@collabora.com>