info: add driver-type
info: add driver-type

With this patch:

    mkdir -p /etc/docker/
    echo '{"features":{"containerd-snapshotter":true}}' > /etc/docker/daemon.json
    dockerd

    docker info
    ...
    Storage Driver: overlayfs
     driver-type: io.containerd.snapshotter.v1
    Logging Driver: json-file

Signed-off-by: Sebastiaan van Stijn <64b2b6d12bfe4baae7dad3d018f8cbf6b0e7a044@gone.nl>

jimjag/docker,cpuguy83/docker,moul/docker,jimjag/docker,Mokolea/docker,mahak/docker,cpuguy83/docker,cpuguy83/docker,moby/moby,trebonian/docker,thaJeztah/docker,Mokolea/docker,mahak/docker,Ramzec/docker,konstruktoid/docker-upstream,moul/docker,konstruktoid/docker-upstream,Mokolea/docker,thaJeztah/docker,moby/moby,Ramzec/docker,Ramzec/docker,trebonian/docker,mahak/docker,jimjag/docker,Ramzec/docker,thaJeztah/docker,mahak/docker,thaJeztah/docker,trebonian/docker,moby/moby,moul/docker,moul/docker,jimjag/docker,konstruktoid/docker-upstream,moby/moby,cpuguy83/docker,konstruktoid/docker-upstream,trebonian/docker,Mokolea/docker