[media] media: radio: correct module license (==> GPL v2)

As per code header comment, changing the driver license entry
to match the correct version.
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/radio/radio-si4713.c

@@ -39,7 +39,7 @@ module_param(radio_nr, int, 0);
 MODULE_PARM_DESC(radio_nr,
 		 "Minor number for radio device (-1 ==> auto assign)");
 
-MODULE_LICENSE("GPL");
+MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Eduardo Valentin <eduardo.valentin@nokia.com>");
 MODULE_DESCRIPTION("Platform driver for Si4713 FM Radio Transmitter");
 MODULE_VERSION("0.0.1");