fix: missing permissions for telegraf ClusterRole (#568)

charts/telegraf-ds/templates/role.yaml

@@ -12,7 +12,7 @@ rules:
     resources: ["pods"]
     verbs: ["get", "list", "watch"]
   - apiGroups: [""]
-    resources: ["nodes/proxy", "nodes/stats"]
+    resources: ["nodes", "nodes/proxy", "nodes/stats", "persistentvolumes"]
     verbs: ["get", "list", "watch"]
 ---
 # Define global role with the default system:aggregate-to-view cluster role and the two rules we just created