staging: vchiq: Release firmware handle on unbind

Use devm_rpi_firmware_get() so as to make sure we release RPi's firmware
interface when unbinding the device.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c

@@ -2734,7 +2734,7 @@ static int vchiq_probe(struct platform_device *pdev)
 		return -ENOENT;
 	}
 
-	drvdata->fw = rpi_firmware_get(fw_node);
+	drvdata->fw = devm_rpi_firmware_get(&pdev->dev, fw_node);
 	of_node_put(fw_node);
 	if (!drvdata->fw)
 		return -EPROBE_DEFER;