mainboard: Add SPDX license headers to Makefiles

To help identify the licenses of the various files contained in the
coreboot source, we've added SPDX headers to the top of all of the
.c and .h files. This extends that practice to Makefiles.

Any file in the coreboot project without a specific license is bound
to the license of the overall coreboot project, GPL Version 2.

This patch adds the GPL V2 license identifier to the top of all
makefiles in the mainboard directory that don't already have an SPDX
license line at the top.

Signed-off-by: Martin Roth <gaumless@gmail.com>
Change-Id: Ic451e68b1ad9ccdf34484dd98bd7fca7e177ef22
Reviewed-on: https://review.coreboot.org/c/coreboot/+/68982
Reviewed-by: Felix Singer <service+coreboot-gerrit@felixsinger.de>
Reviewed-by: Yidi Lin <yidilin@google.com>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Reviewed-by: Tim Crawford <tcrawford@system76.com>
Reviewed-by: Elyes Haouas <ehaouas@noos.fr>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/mainboard/google/dedede/variants/baseboard/Makefile.inc b/src/mainboard/google/dedede/variants/baseboard/Makefile.inc
index 2c3f2f6989..a58371afe9 100644
--- a/src/mainboard/google/dedede/variants/baseboard/Makefile.inc
+++ b/src/mainboard/google/dedede/variants/baseboard/Makefile.inc
@@ -1,3 +1,5 @@
+## SPDX-License-Identifier: GPL-2.0-only
+
 bootblock-y += gpio.c
 
 romstage-y += gpio.c