treewide: Convert more license headers to SPDX style

Change-Id: Ia3de79c7d71049da00ed108829eac6cb49ff3ed6
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41205
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/drivers/crb/tpm.c

@@ -1,7 +1,5 @@
-/*.
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- *
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
  * This is a driver for a CRB Interface.
  *
  * The general flow looks like this:

src/drivers/crb/tpm.h

@@ -1,10 +1,5 @@
-/*
- * Copyright 2016 The Chromium OS Authors. All rights reserved.
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- *
- * This is a driver for a Command Response Buffer Interface
- */
+/* SPDX-License-Identifier: BSD-3-Clause */
+/* This is a driver for a Command Response Buffer Interface */
 
 /* CRB driver */
 /* address of locality 0 (CRB) */