mtd: omap: fix mtd devices not showing up

Since commit 6d178ef2fd5e ("mtd: nand: Move ELM driver and rename as
omap_elm"), I don't have any mtd devices present on my am335x. This
changes the link order of the omap_elm and omap2 objects, causing them
to probe in the wrong order.

To fix this, make elm_config defer probing until the omap_elm driver is
actually loaded.

Signed-off-by: Frans Klaver <frans.klaver@xsens.com>
Acked-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/mtd/nand/omap_elm.c

@@ -115,7 +115,7 @@ int elm_config(struct device *dev, enum bch_ecc bch_type,
 
 	if (!info) {
 		dev_err(dev, "Unable to configure elm - device not probed?\n");
-		return -ENODEV;
+		return -EPROBE_DEFER;
 	}
 	/* ELM cannot detect ECC errors for chunks > 1KB */
 	if (ecc_step_size > ((ELM_ECC_SIZE + 1) / 2)) {