kbuild: Add copyright to modpost.c

It seems popular to protect your work with copyright, so I decided to do
so for modpost which I patch a great deal atm.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

scripts/mod/modpost.c

@@ -2,7 +2,7 @@
  *
  * Copyright 2003       Kai Germaschewski
  * Copyright 2002-2004  Rusty Russell, IBM Corporation
- *
+ * Copyright 2006       Sam Ravnborg
  * Based in part on module-init-tools/depmod.c,file2alias
  *
  * This software may be used and distributed according to the terms