Here are patches that add the WireGuard [0] userspace tools and a Linux
kernel patch that can be used to build WireGuard support into the kernel.

When building linux-libre with the WireGuard patch, WireGuard is built
as a module that will be loaded on demand.

The second patch in the series is just for demonstration and personal
use until WireGuard is added to the official kernel tree; I don't think
we need to add it to Guix.

Feedback?

[0] https://www.wireguard.com/