Move cgroup v1 in maintenance mode

Signed-off-by: Harshal Patil <[email protected]>

Author: harche

keps/prod-readiness/sig-node/4569.yaml

@@ -0,0 +1,6 @@
+# The KEP must have an approver from the
+# "prod-readiness-approvers" group
+# of http://git.k8s.io/enhancements/OWNERS_ALIASES
+kep-number: 4569
+stable:
+  approver: "@deads2k"