Fix the NAND size overflow issue.

When the total size of all NAND devices exceeds 4 GiB, the size  will
overflow. This patch tries to fix this.

Note that we still have a problem when a single NAND device is bigger
than 4 GiB: then the overflow would actually happen earlier, i. e.
when storing the size in nand_info[].size, as nand_info[].size is an
"u_int32_t".

Signed-off-by: Jason Jin <Jason.jin@freescale.com>
Signed-off-by: Wolfgang Denk <wd@denx.de>

drivers/mtd/nand/nand.c

@@ -63,11 +63,11 @@ void nand_init(void)
 	unsigned int size = 0;
 	for (i = 0; i < CFG_MAX_NAND_DEVICE; i++) {
 		nand_init_chip(&nand_info[i], &nand_chip[i], base_address[i]);
-		size += nand_info[i].size;
+		size += nand_info[i].size / 1024;
 		if (nand_curr_device == -1)
 			nand_curr_device = i;
 	}
-	printf("%u MiB\n", size / (1024 * 1024));
+	printf("%u MiB\n", size / 1024);
 
 #ifdef CFG_NAND_SELECT_DEVICE
 	/*