clk: si570: Migrate to clk_hw based OF and registration APIs

Now that we have clk_hw based provider APIs to register clks, we
can get rid of struct clk pointers while registering clks in
these drivers, allowing us to move closer to a clear split of
consumer and provider clk APIs.

Cc: Guenter Roeck <[e-mail]>
Cc: Sören Brinkmann <[e-mail]>
Signed-off-by: Stephen Boyd <[e-mail]>
Signed-off-by: Stephen Boyd <[e-mail]>

drivers/clk/clk-si570.c

···
 {
 	struct clk_si570 *data;
 	struct clk_init_data init;
-	struct clk *clk;
 	u32 initial_fout, factory_fout, stability;
 	int err;
 	enum clk_si570_variant variant = id->driver_data;
···
 	if (err)
 		return err;
 
-	clk = devm_clk_register(&client->dev, &data->hw);
-	if (IS_ERR(clk)) {
+	err = devm_clk_hw_register(&client->dev, &data->hw);
+	if (err) {
 		dev_err(&client->dev, "clock registration failed\n");
-		return PTR_ERR(clk);
+		return err;
 	}
-	err = of_clk_add_provider(client->dev.of_node, of_clk_src_simple_get,
-			clk);
+	err = of_clk_add_hw_provider(client->dev.of_node, of_clk_hw_simple_get,
+				     &data->hw);
 	if (err) {
 		dev_err(&client->dev, "unable to add clk provider\n");
 		return err;
···
 	/* Read the requested initial output frequency from device tree */
 	if (!of_property_read_u32(client->dev.of_node, "clock-frequency",
 				&initial_fout)) {
-		err = clk_set_rate(clk, initial_fout);
+		err = clk_set_rate(data->hw.clk, initial_fout);
 		if (err) {
 			of_clk_del_provider(client->dev.of_node);
 			return err;