BugLink: https://bugs.launchpad.net/bugs/1861284

Add support for building, signing, and shipping the wireguard.ko from
the wireguard-dkms package.  Drop this into the linux-modules package.
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com
Signed-off-by: Ian May <ian.may@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>