security/tpm: Use SPDX identifiers

Also adjust a few comments to follow the style guide.

Change-Id: I22001320f2ce1f0db348e0f7fabc5a65b50ba53e
Signed-off-by: Jacob Garber <jgarber1@ualberta.ca>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41600
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
diff --git a/src/security/tpm/tss/tcg-2.0/tss_marshaling.c b/src/security/tpm/tss/tcg-2.0/tss_marshaling.c
index eff1acd..f31c7d0 100644
--- a/src/security/tpm/tss/tcg-2.0/tss_marshaling.c
+++ b/src/security/tpm/tss/tcg-2.0/tss_marshaling.c
@@ -1,9 +1,4 @@
-/*
- * Copyright 2016 The Chromium OS Authors. All rights reserved.
- * Copyright (c) 2018 Eltan B.V.
- * 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 */
 
 #include <commonlib/iobuf.h>
 #include <console/console.h>