common: use get_nand_dev_by_index()

As part of preparation for nand DM conversion the new API has been
introduced to remove direct access to nand_info array. So, use it here
instead of accessing to nand_info array directly.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
diff --git a/common/fb_nand.c b/common/fb_nand.c
index c8c79e9..3d027d4 100644
--- a/common/fb_nand.c
+++ b/common/fb_nand.c
@@ -59,7 +59,7 @@
 		return -EINVAL;
 	}
 
-	*mtd = nand_info[dev->id->num];
+	*mtd = get_nand_dev_by_index(dev->id->num);
 
 	return 0;
 }
diff --git a/common/splash_source.c b/common/splash_source.c
index ee055dd..867a798 100644
--- a/common/splash_source.c
+++ b/common/splash_source.c
@@ -47,9 +47,10 @@
 #ifdef CONFIG_CMD_NAND
 static int splash_nand_read_raw(u32 bmp_load_addr, int offset, size_t read_size)
 {
-	return nand_read_skip_bad(nand_info[nand_curr_device], offset,
+	struct mtd_info *mtd = get_nand_dev_by_index(nand_curr_device);
+	return nand_read_skip_bad(mtd, offset,
 				  &read_size, NULL,
-				  nand_info[nand_curr_device]->size,
+				  mtd->size,
 				  (u_char *)bmp_load_addr);
 }
 #else