util: Add SPDX header, replacing boiler plate where applicable

In a few cases a license was added: Stuff coming from Linux is
"GPL-2.0" (not GPL-2.0-only!), build-release is by me and got the
usual GPL-2.0-only treatment. uio_usbdebug and spkmodem had their
licenses propagate to all their files.

Change-Id: Ia5712bbaa417cb9e937834512351fcc0acfa16be
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41202
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

util/vgabios/device.c

@@ -1,13 +1,4 @@
-/******************************************************************************
- * This program and the accompanying materials
- * are made available under the terms of the BSD License
- * which accompanies this distribution, and is available at
- * http://www.opensource.org/licenses/bsd-license.php
- *
- * Contributors:
- *     IBM Corporation - initial implementation
- *****************************************************************************/
-
+/* SPDX-License-Identifier: BSD-2-Clause */
 
 #include <stdtypes.h>