mtd: mtdpart: Don't create platform device that'll never probe

These "nvmem-cells" platform devices never get probed because there's no
platform driver for it and it's never used anywhere else. So it's a
waste of memory. These devices also cause fw_devlink to block nvmem
consumers of "nvmem-cells" partition from probing because the supplier
device never probes.

So stop creating platform devices for nvmem-cells partitions to avoid
wasting memory and to avoid blocking probing of consumers.

Reported-by: Maxim Kiselev <[e-mail]>
Fixes: bcdf0315a61a ("mtd: call of_platform_populate() for MTD partitions")
Signed-off-by: Saravana Kannan <[e-mail]>
Tested-by: Maksim Kiselev <[e-mail]>
Tested-by: Douglas Anderson <[e-mail]>
Tested-by: Geert Uytterhoeven <[e-mail]>
Tested-by: Luca Weiss <[e-mail]> # qcom/sm7225-fairphone-fp4
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/mtd/mtdpart.c

···
 {
 	struct mtd_part_parser *parser;
 	struct device_node *np;
+	struct device_node *child;
 	struct property *prop;
 	struct device *dev;
 	const char *compat;
···
 		of_node_get(np);
 	else
 		np = of_get_child_by_name(np, "partitions");
+
+	/*
+	 * Don't create devices that are added to a bus but will never get
+	 * probed. That'll cause fw_devlink to block probing of consumers of
+	 * this partition until the partition device is probed.
+	 */
+	for_each_child_of_node(np, child)
+		if (of_device_is_compatible(child, "nvmem-cells"))
+			of_node_set_flag(child, OF_POPULATED);
 
 	of_property_for_each_string(np, "compatible", prop, compat) {
 		parser = mtd_part_get_compatible_parser(compat);