elf2rel: Add copyright header

PistonMiner · Zephiles · commit 6ef12c76bb08 · 2020-06-23T19:03:00.000-05:00
diff --git a/ttyd-tools/elf2rel/elf2rel.cpp b/ttyd-tools/elf2rel/elf2rel.cpp
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+// Copyright 2019 Linus S. (aka PistonMiner)
+
 #include "elf2rel.h"
 
 #include <elfio/elfio.hpp>
diff --git a/ttyd-tools/elf2rel/elf2rel.h b/ttyd-tools/elf2rel/elf2rel.h
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+// Copyright 2019 Linus S. (aka PistonMiner)
+
 #pragma once
 
 #include <vector>
