mtd: rawnand: marvell: Fix probe error path

Ensure all chips are deregistered and cleaned in case of error during
the probe.

Fixes: 02f26ecf ("mtd: nand: add reworked Marvell NAND controller driver")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200424164501.26719-5-miquel.raynal@bootlin.com