Yocto packaging

Yocto has fairly straightforward support for Rust code. It works best when all dependencies are available from crates.io. Then one can just use the Yocto tooling without any manual tweaks.

The currently packaged daemons can be found at https://git.yoctoproject.org/meta-virtualization/tree/recipes-extended/vhost-device/ .

The .inc files are generated via bitbake -c update_crates <recipe>.