Upstream OE/Yocto uses a LICENSE file to describe the metadata license. Apply this format to the AGL repos as well.

AGL re-uses the upstream MIT license for the metadata.

E.g.:

• http://git.yoctoproject.org/cgit/cgit.cgi/poky/tree/LICENSE
• http://git.yoctoproject.org/cgit/cgit.cgi/poky/tree/LICENSE.MIT
• http://git.yoctoproject.org/cgit/cgit.cgi/poky/tree/LICENSE.GPL-2.0-only

Lateron: A Subtask will be to apply SPDX tags.