[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/include/asm-parisc/pdc_chassis.h b/include/asm-parisc/pdc_chassis.h
index adac9ac..a609273 100644
--- a/include/asm-parisc/pdc_chassis.h
+++ b/include/asm-parisc/pdc_chassis.h
@@ -6,9 +6,8 @@
  *
  *
  *      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, 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