longcheer: ensure the plugin on handles devices it's supposed to

Other devices from the same vendor (x220) need to be handled by
the x22x plugin, so Longcheer can't just rely on the vendor ID
match to know whether it should handle the modem.

plugins/mm-plugin-longcheer.c

@@ -87,6 +87,12 @@ supports_port (MMPluginBase *base,
     if (vendor != 0x1c9e && vendor != 0x1bbb)
         return MM_PLUGIN_SUPPORTS_PORT_UNSUPPORTED;
 
+    /* Some TAMobile devices are different chipsets and should be handled
+     * by other plugins, so only handle LONGCHEER tagged devices here.
+     */
+    if (g_udev_device_get_property_as_boolean (port, "ID_MM_LONGCHEER_TAGGED") == FALSE)
+        return MM_PLUGIN_SUPPORTS_PORT_UNSUPPORTED;
+
     if (mm_plugin_base_get_cached_port_capabilities (base, port, &cached)) {
         level = get_level_for_capabilities (cached);
         if (level) {