mux: adgs1408: use the correct MODULE_LICENSE

The file is GPL v2 or later.
Acked-by: Mircea Caprioru <mircea.caprioru@analog.com>
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/mux/adgs1408.c

@@ -128,4 +128,4 @@ module_spi_driver(adgs1408_driver);
 
 MODULE_AUTHOR("Mircea Caprioru <mircea.caprioru@analog.com>");
 MODULE_DESCRIPTION("Analog Devices ADGS1408 MUX driver");
-MODULE_LICENSE("GPL v2");
+MODULE_LICENSE("GPL");