Fix route reconciler

[discordianfish]

The controller-manager can't reconcile node routes (I'm not sure why it's even trying..?).
It looks for route tables tagged with 'kubernetes'. Whatever this is suppose to do, it should use DomainName as cluster identifier:

E0122 16:12:37.084672       1 route_controller.go:116] Couldn't reconcile node routes: error listing routes: found multiple matching AWS route tables for AWS cluster: kubernetes

[discordianfish]

Looks like we need to do something similar to kubernetes-retired/kube-aws#1341