mb/google/octopus: Use SPDX for GPL-2.0-only files

Done with sed and God Lines. Only done for C-like code for now.

Change-Id: I8076155330100982de82d410b6579ac99ed89e7b
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/40187
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/mainboard/google/octopus/variants/yorp/gpio.c b/src/mainboard/google/octopus/variants/yorp/gpio.c
index ffc7e4a..775811b 100644
--- a/src/mainboard/google/octopus/variants/yorp/gpio.c
+++ b/src/mainboard/google/octopus/variants/yorp/gpio.c
@@ -1,16 +1,5 @@
-/*
- * 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.
- */
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* This file is part of the coreboot project. */
 
 #include <baseboard/gpio.h>
 #include <baseboard/variants.h>