of: Don't create device for OPP tables

The OPP tables are present as separate nodes, whose phandle is used in
the "operating-points-v2" property of devices. Currently the OF core
creates a device for the OPP table unconditionally, which is not used by
any kernel code.

This patch creates another OF device_id table for the nodes which must
be skipped while creating devices and OPP is the only user of it for now.
Reported-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>

drivers/of/platform.c

@@ -32,6 +32,11 @@ const struct of_device_id of_default_bus_match_table[] = {
 	{} /* Empty terminated list */
 };
 
+static const struct of_device_id of_skipped_node_table[] = {
+	{ .compatible = "operating-points-v2", },
+	{} /* Empty terminated list */
+};
+
 static int of_dev_node_match(struct device *dev, void *data)
 {
 	return dev->of_node == data;
@@ -356,6 +361,12 @@ static int of_platform_bus_create(struct device_node *bus,
 		return 0;
 	}
 
+	/* Skip nodes for which we don't want to create devices */
+	if (unlikely(of_match_node(of_skipped_node_table, bus))) {
+		pr_debug("%s() - skipping %pOF node\n", __func__, bus);
+		return 0;
+	}
+
 	if (of_node_check_flag(bus, OF_POPULATED_BUS)) {
 		pr_debug("%s() - skipping %pOF, already populated\n",
 			__func__, bus);