src/cpu/amd: Update/Add license headers to all files

Change-Id: I1e0b2b9086db6b3c2f716d9400a83eb60b2ce222
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/18403
Tested-by: build bot (Jenkins)
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
diff --git a/src/cpu/amd/agesa/family15tn/udelay.c b/src/cpu/amd/agesa/family15tn/udelay.c
index 5873237..cc673e2 100644
--- a/src/cpu/amd/agesa/family15tn/udelay.c
+++ b/src/cpu/amd/agesa/family15tn/udelay.c
@@ -1,10 +1,23 @@
 /*
- * udelay() impementation for SMI handlers
- * This is neat in that it never writes to hardware registers, and thus does not
- * modify the state of the hardware while servicing SMIs.
+ * This file is part of the coreboot project.
  *
  * Copyright (C) 2014 Alexandru Gagniuc <mr.nuke.me@gmail.com>
- * Subject to the GNU GPL v2, or (at your option) any later version.
+ *
+ * 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.
+ */
+
+/*
+ * udelay() impementation for SMI handlers
+ * This is neat in that it never writes to hardware registers, and thus does
+ *  not modify the state of the hardware while servicing SMIs.
  */
 
 #include <cpu/x86/msr.h>