drm/client: Export drm_client_dev_unregister()

Export drm_client_dev_unregister() for use by the i915 driver. The
driver does not use drm_dev_unregister(), so it has to clean up the
in-kernel DRM clients by itself.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jouni Högander <jouni.hogander@intel.com>
Acked-by: Lucas De Marchi <lucas.demarchi@intel.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20240409081029.17843-2-tzimmermann@suse.deSigned-off-by: Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/drm_client.c

@@ -172,6 +172,18 @@ void drm_client_release(struct drm_client_dev *client)
 }
 EXPORT_SYMBOL(drm_client_release);
 
+/**
+ * drm_client_dev_unregister - Unregister clients
+ * @dev: DRM device
+ *
+ * This function releases all clients by calling each client's
+ * &drm_client_funcs.unregister callback. The callback function
+ * is responsibe for releaseing all resources including the client
+ * itself.
+ *
+ * The helper drm_dev_unregister() calls this function. Drivers
+ * that use it don't need to call this function themselves.
+ */
 void drm_client_dev_unregister(struct drm_device *dev)
 {
 	struct drm_client_dev *client, *tmp;
@@ -191,6 +203,7 @@ void drm_client_dev_unregister(struct drm_device *dev)
 	}
 	mutex_unlock(&dev->clientlist_mutex);
 }
+EXPORT_SYMBOL(drm_client_dev_unregister);
 
 /**
  * drm_client_dev_hotplug - Send hotplug event to clients