staging: alarm-dev: Set the license to GPL

Adding "GPL" license to fix a warning while compiling as
module.

CC: Brian Swetland <swetland@google.com>
Signed-off-by: Pramod Gurav <pramod.gurav.etc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/android/alarm-dev.c

@@ -443,4 +443,4 @@ static void  __exit alarm_dev_exit(void)
 
 module_init(alarm_dev_init);
 module_exit(alarm_dev_exit);
-
+MODULE_LICENSE("GPL");