drm: update PCIGART support from CVS

In order to work on FreeBSD the gart needed to use a local mapping
This patch moves the mainline to the new code and aligns some comment
changes

From: Eric Anholt <anholt@freebsd.org>
Signed-off-by: Dave Airlie <airlied@linux.ie>
diff --git a/drivers/char/drm/r128_state.c b/drivers/char/drm/r128_state.c
index 6aeeb4b..caeecc2 100644
--- a/drivers/char/drm/r128_state.c
+++ b/drivers/char/drm/r128_state.c
@@ -1,7 +1,7 @@
 /* r128_state.c -- State support for r128 -*- linux-c -*-
  * Created: Thu Jan 27 02:53:43 2000 by gareth@valinux.com
- *
- * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
+ */
+/* Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
  * All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a