device-types: enable lxc in base-grub.jinja2

Enable running LXC containers alongside devices that use GRUB.
Signed-off-by: Guillaume Tucker <guillaume.tucker@collabora.com>

etc/dispatcher-config/device-types/base-grub.jinja2

@@ -62,12 +62,15 @@ actions:
   deploy:
     connections:
       serial:
+      lxc:
     methods:
       tftp:
       nbd:
+      lxc:
   boot:
     connections:
       serial:
+      lxc:
     methods:
       grub:
         parameters: