mainboard/intel: Update license headers

Update all of the license headers to make sure they are compliant
with coreboot's license header policy.

Change-Id: I260c1ae8d0f7306dd0c72c9ca05f0789cd915a61
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/14322
Tested-by: build bot (Jenkins)
Reviewed-by: Damien Zammit <damien@zamaudio.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
diff --git a/src/mainboard/intel/d945gclf/cstates.c b/src/mainboard/intel/d945gclf/cstates.c
index 2d543ff..f683756 100644
--- a/src/mainboard/intel/d945gclf/cstates.c
+++ b/src/mainboard/intel/d945gclf/cstates.c
@@ -1,3 +1,16 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * 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; version 2 of the License.
+ *
+ * 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.
+ */
+
 #include <device/device.h>
 #include <arch/x86/include/arch/acpigen.h>