More device API cleanup
Drop gdk_device_get_device_type(), drop gdk_device_get_associated_device(), hide gdk_device_list_physical_devices() and rename gdk_seat_get_physical_devices().
Drop gdk_device_get_device_type(), drop gdk_device_get_associated_device(), hide gdk_device_list_physical_devices() and rename gdk_seat_get_physical_devices().