Allow namespaces readonly crd-controller rbac

Readonly access to namespaces is needed by the
image-reflector-controller to support the cross-namespace accessFrom
functionality introduced in image-reflector-controller#162.

Signed-off-by: Aurel Canciu <aurelcanciu@gmail.com>

manifests/rbac/controller.yaml

@@ -21,6 +21,7 @@ rules:
 - apiGroups:
   - ""
   resources:
+  - namespaces
   - secrets
   verbs:
   - get