chio: Add missing SPDX-License-Identifier tags to files

[tuukka.pasanen_ilmi.fi]

Summary

Some files under bin/chio were missing SPDX-License-Identifier-tag.
Commit adds missing tags:

• bin/chio/chio.c: BSD-4-Clause
• bin/chio/defs.h: BSD-4-Clause
• bin/chio/pathnames.h: BSD-4-Clause

[tuukka.pasanen_ilmi.fi]

Updated using git-arc to make sure they are in sync