Complete renaming of gdk_enable_multidevice()

The function was renamed in commit c4a5c2ed4, but some places were
missed, most notably the public header.

docs/reference/gdk/gdk3-sections.txt

@@ -703,7 +703,7 @@ GdkDeviceKey
 GdkDeviceAxis
 GdkAxisUse
 GdkGrabOwnership
-gdk_enable_multidevice
+gdk_disable_multidevice
 gdk_device_manager_get_display
 gdk_device_manager_list_devices
 gdk_device_manager_get_client_pointer

gdk/gdkdevicemanager.c

@@ -85,8 +85,8 @@
  *
  * In order to query the device hierarchy and be aware of changes in the device hierarchy (such as
  * virtual devices being created or removed, or physical devices being plugged or unplugged), GDK
- * provides #GdkDeviceManager. On X11, multidevice support is implemented through XInput 2. If
- * gdk_enable_multidevice() is called, the XInput 2.x #GdkDeviceManager implementation will be used
+ * provides #GdkDeviceManager. On X11, multidevice support is implemented through XInput 2. Unless
+ * gdk_disable_multidevice() is called, the XInput 2.x #GdkDeviceManager implementation will be used
  * as input source, else either the core or XInput 1.x implementations will be used.
  */
 

gdk/gdkmain.h

@@ -72,7 +72,7 @@ void                  gdk_pre_parse_libgtk_only           (void);
  * Returns: the resulting locale.
  */
 gchar*                gdk_set_locale                      (void);
-void                  gdk_enable_multidevice              (void);
+void                  gdk_disable_multidevice             (void);
 
 G_CONST_RETURN gchar *gdk_get_program_class               (void);
 void                  gdk_set_program_class               (const gchar    *program_class);