lxd/network/driver/physical: Adds ovn.ingress_mode config key
lxd/network/driver/physical: Adds ovn.ingress_mode config key

Allows specifying how external OVN NIC IPs are advertised to the uplink; either "l2proxy" (default) or "routed".

Signed-off-by: Thomas Parrott <6b778ce645fb0e3dde76d79eccad490955b1ae74@canonical.com>

stgraber/lxd,hallyn/lxd,lxc/lxd,lxc/lxd,lxc/lxd,hallyn/lxd,stgraber/lxd,stgraber/lxd,hallyn/lxd,atxwebs/lxd,atxwebs/lxd,stgraber/lxd,stgraber/lxd,atxwebs/lxd,lxc/lxd,stgraber/lxd,lxc/lxd,atxwebs/lxd,lxc/lxd,lxc/lxd,hallyn/lxd,hallyn/lxd,hallyn/lxd,stgraber/lxd