firmware: rpi: Only create clocks device if we don't have a node for it

The firmware clocks driver was previously probed through a platform_device
created by the firmware driver.

Since we will now have a node for that clocks driver, we need to create the
device only in the case where there's no node for it already.
Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/72114c4287ebda2dbd952ea238d4489d359897e5.1592210452.git-series.maxime@cerno.techSigned-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/firmware/raspberrypi.c

@@ -208,6 +208,20 @@ rpi_register_hwmon_driver(struct device *dev, struct rpi_firmware *fw)
 
 static void rpi_register_clk_driver(struct device *dev)
 {
+	struct device_node *firmware;
+
+	/*
+	 * Earlier DTs don't have a node for the firmware clocks but
+	 * rely on us creating a platform device by hand. If we do
+	 * have a node for the firmware clocks, just bail out here.
+	 */
+	firmware = of_get_compatible_child(dev->of_node,
+					   "raspberrypi,firmware-clocks");
+	if (firmware) {
+		of_node_put(firmware);
+		return;
+	}
+
 	rpi_clk = platform_device_register_data(dev, "raspberrypi-clk",
 						-1, NULL, 0);
 }