add GPLv2 license disclaimer

rtl8168-eeprom.c

@@ -9,8 +9,23 @@
 #include <sys/fcntl.h>
 #include <sys/mman.h>
 
-/* utility to program MAC address of RTL8168 / RTL8111E EEPROM 
+/* utility to program MAC address of RTL8168 / RTL8111E EEPROM
  * (C) 2015 by Harald Welte <hwelte@sysmocom.de>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301 USA.
  */
 
 static void die(char *msg, ...)