base-manager: reprobe device on late port additions

There is no guarantee from the kernel that the ports of a given device
will all be notified via uevents on a timely manner. We assume it, but
we cannot be completely sure.

There are two main scenarios that we have been seen when the ports of a
device are not notified close enough to each other:

 * A modem object is created, but not with the desired control protocol.
   E.g. a QMI or MBIM modem would end up controlled via AT commands if
   the cdc-wdm port was added too late.

 * A modem object is not created at all, and the device object was
   removed completely. E.g. when the net port addition in a QMI or MBIM
   modem happens too late.

In order to avoid those cases, we will now fully reprobe all the ports
of the device from scratch whenever a new valid port addition happens
after the initial probing of the device has already been completed. If a
modem object is available at that time, we will remove it right away.

src/mm-plugin-manager.h

@@ -67,6 +67,14 @@ gboolean         mm_plugin_manager_device_support_check_cancel (MMPluginManager
 MMPlugin *       mm_plugin_manager_device_support_check_finish (MMPluginManager      *self,
                                                                 GAsyncResult         *res,
                                                                 GError              **error);
+
+gboolean         mm_plugin_manager_device_support_check_ongoing (MMPluginManager *self,
+                                                                 MMDevice        *device);
+
+gboolean         mm_plugin_manager_device_support_check_add_port (MMPluginManager *self,
+                                                                  MMDevice        *device,
+                                                                  MMKernelDevice  *port);
+
 MMPlugin        *mm_plugin_manager_peek_plugin                 (MMPluginManager      *self,
                                                                 const gchar          *plugin_name);
 const gchar    **mm_plugin_manager_get_subsystems              (MMPluginManager      *self);