[PARISC] Clarify pdc_stable license terms

pdc_stable.c is explicitly licensed under GPL version 2.

Signed-off-by: Thibaut VARENE <varenet@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
diff --git a/drivers/parisc/pdc_stable.c b/drivers/parisc/pdc_stable.c
index a28e178..4e53be9 100644
--- a/drivers/parisc/pdc_stable.c
+++ b/drivers/parisc/pdc_stable.c
@@ -4,9 +4,8 @@
  *    Copyright (C) 2005-2006 Thibaut VARENE <varenet@parisc-linux.org>
  *
  *    This program is free software; you can redistribute it and/or modify
- *    it under the terms of the GNU General Public License as published by
- *    the Free Software Foundation; either version 2 of the License, or
- *    (at your option) any later version.
+ *    it under the terms of the GNU General Public License, version 2, as
+ *    published by the Free Software Foundation.
  *
  *    This program is distributed in the hope that it will be useful,
  *    but WITHOUT ANY WARRANTY; without even the implied warranty of