linux-imx

mtd: rawnand: Get rid of the duplicate nand_chip forward declaration

There's already a forward declaration of nand_chip at the beginning of
the file. Get rid of this one.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>