e1000: Fix date string in Makefile

I forgot to update the date string in the Makefile last time.
Signed-off-by: NAuke Kok <auke-jan.h.kok@intel.com>

drivers/net/e1000/Makefile

 ################################################################################
 #
 # 
-# Copyright(c) 1999 - 2003 Intel Corporation. All rights reserved.
+# Copyright(c) 1999 - 2006 Intel Corporation. All rights reserved.
 # 
 # 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