controller: add kubeconfig reconciler (#906)

Co-authored-by: Abhijith Ravindra <137736216+abhijith-darshan@users.noreply.github.com>

cmd/greenhouse/controllers.go

@@ -41,6 +41,7 @@ var knownControllers = map[string]func(controllerName string, mgr ctrl.Manager)
 	// Cluster controllers
 	"bootStrap":         (&clustercontrollers.BootstrapReconciler{}).SetupWithManager,
 	"clusterReconciler": startClusterReconciler,
+	"kubeconfig":        (&clustercontrollers.KubeconfigReconciler{}).SetupWithManager,
 }
 
 // knownControllers lists the name of known controllers.