staging: fsl-mc: implement uevent callback and set the modalias

Replace placeholder code in the uevent callback to properly
set the MODALIAS env variable.
Signed-off-by: NStuart Yoder <stuart.yoder@nxp.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/fsl-mc/bus/mc-bus.c

@@ -78,7 +78,13 @@ static int fsl_mc_bus_match(struct device *dev, struct device_driver *drv)
  */
 static int fsl_mc_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
-	pr_debug("%s invoked\n", __func__);
+	struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
+
+	if (add_uevent_var(env, "MODALIAS=fsl-mc:v%08Xd%s",
+			   mc_dev->obj_desc.vendor,
+			   mc_dev->obj_desc.type))
+		return -ENOMEM;
+
 	return 0;
 }