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>

drivers/mtd/nand/bbt.c

@@ -9,6 +9,7 @@
 
 #define pr_fmt(fmt)	"nand-bbt: " fmt
 
+#include <common.h>
 #include <linux/mtd/nand.h>
 #ifndef __UBOOT__
 #include <linux/slab.h>

drivers/mtd/nand/core.c

@@ -9,6 +9,7 @@
 
 #define pr_fmt(fmt)	"nand: " fmt
 
+#include <common.h>
 #ifndef __UBOOT__
 #include <linux/module.h>
 #endif