mtd: nand: add includes in NAND core to avoid warnings

Because of the include's game, when some files are compiled for a SPI
NAND device, no warning appears. But when it is for a raw NAND device,
GCC complains. Fix these warning by including <common.h>.

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