mtd: rawnand: fsl_elbc: Let .probe retry if local bus is missing

If during probe fsl_lbc_ctrl_dev is NULL that might just be because the
fsl_lbc driver didn't bind yet. So return -EPROBE_DEFER in this case to
make the driver core retry probing later.

Signed-off-by: Uwe Kleine-König <[e-mail]>
Signed-off-by: Miquel Raynal <[e-mail]>
Link: https://lore.kernel.org/linux-mtd/[e-mail]

drivers/mtd/nand/raw/fsl_elbc_nand.c

···
 	struct mtd_info *mtd;
 
 	if (!fsl_lbc_ctrl_dev || !fsl_lbc_ctrl_dev->regs)
-		return -ENODEV;
+		return dev_err_probe(&pdev->dev, -EPROBE_DEFER, "lbc_ctrl_dev missing\n");
+
 	lbc = fsl_lbc_ctrl_dev->regs;
 	dev = fsl_lbc_ctrl_dev->dev;