nand: Embed mtd_info in struct nand_chip

nand_info[] is now an array of pointers, with the actual mtd_info
instance embedded in struct nand_chip.

This is in preparation for syncing the NAND code with Linux 4.6,
which makes the same change to struct nand_chip.  It's in a separate
commit due to the large amount of changes required to accommodate the
change to nand_info[].

Signed-off-by: Scott Wood <oss@buserror.net>
diff --git a/cmd/bootm.c b/cmd/bootm.c
index 24f1054..f5e91f4 100644
--- a/cmd/bootm.c
+++ b/cmd/bootm.c
@@ -461,7 +461,7 @@
 	printf("\n");
 
 	for (nand_dev = 0; nand_dev < CONFIG_SYS_MAX_NAND_DEVICE; nand_dev++) {
-		mtd = &nand_info[nand_dev];
+		mtd = nand_info[nand_dev];
 		if (!mtd->name || !mtd->size)
 			continue;