tree-wide: add spdx header on all scripts and helpers

Even though many of those scripts are very simple, it is easier to include
the header than to try to say whether each of those files is trivial enough
not to require one.

src/basic/af-to-name.awk

@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
 BEGIN{
         print "static const char* const af_names[] = { "
 }

src/basic/arphrd-to-name.awk

@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
 BEGIN{
         print "const char *arphrd_to_name(int id) {"
         print "        switch(id) {"

src/basic/cap-to-name.awk

@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
 BEGIN{
         print "static const char* const capability_names[] = { "
 }

src/basic/errno-to-name.awk

@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
 BEGIN{
         print "static const char* const errno_names[] = { "
 }

src/basic/generate-af-list.sh

@@ -1,4 +1,5 @@
 #!/bin/sh
+# SPDX-License-Identifier: LGPL-2.1-or-later
 set -eu
 
 $1 -E -dM -include sys/socket.h -include "$2" -include "$3" - </dev/null | \

src/basic/generate-arphrd-list.sh

@@ -1,4 +1,5 @@
 #!/bin/sh
+# SPDX-License-Identifier: LGPL-2.1-or-later
 set -eu
 
 $1 -dM -include linux/if_arp.h -include "$2" - </dev/null | \

src/basic/generate-cap-list.sh

@@ -1,4 +1,5 @@
 #!/bin/sh
+# SPDX-License-Identifier: LGPL-2.1-or-later
 set -eu
 
 $1 -dM -include linux/capability.h -include "$2" -include "$3" - </dev/null | \

src/basic/generate-errno-list.sh

@@ -1,4 +1,5 @@
 #!/bin/sh
+# SPDX-License-Identifier: LGPL-2.1-or-later
 set -eu
 
 $1 -dM -include errno.h - </dev/null | \

src/basic/linux/update.sh

@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-
+# SPDX-License-Identifier: LGPL-2.1-or-later
 set -eu
 
 for i in *.h */*.h; do