Fixed GPLv2 license text in the start.

src/common/scm_rev.cpp.in

@@ -1,5 +1,5 @@
 // Copyright 2014 Citra Emulator Project
-// Licensed under GPLv2
+// Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
 #include "common/scm_rev.h"