mtd: rawnand: ifc: set chip->of_node to nand@0 child node if present

The nand-controller.yaml binding requires a child node (e.g. nand@0) under
the NAND controller. However, the driver currently assigns the controller's
of_node directly to the NAND chip.

Search for the first child node with the "nand" prefix and assign it to
chip->of_node. This filters out properties such as "partition" that may be
placed under the controller node in some older DTS files.

Fall back to using the controller's of_node if no suitable child node is
found to maintain backward compatibility.

This issue went unnoticed because the default behavior works for most NAND
chips.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

Author: nxpfrankli

drivers/mtd/nand/raw/fsl_ifc_nand.c

@@ -7,6 +7,7 @@
  * Author: Dipen Dudhat <Dipen.Dudhat@freescale.com>
  */
 
+#include <linux/cleanup.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/types.h>
@@ -863,7 +864,14 @@ static int fsl_ifc_chip_init(struct fsl_ifc_mtd *priv)
 
 	/* Fill in fsl_ifc_mtd structure */
 	mtd->dev.parent = priv->dev;
-	nand_set_flash_node(chip, priv->dev->of_node);
+
+	struct device_node *np __free(device_node) =
+		of_get_next_child_with_prefix(priv->dev->of_node, NULL, "nand");
+
+	if (np)
+		nand_set_flash_node(chip, np);
+	else
+		nand_set_flash_node(chip, priv->dev->of_node);
 
 	/* fill in nand_chip structure */
 	/* set up function call table */