update JSON IAM policy

Author: mletalie

modules/osd-persistent-storage-csi-efs-sts.adoc

@@ -40,7 +40,8 @@ If you perform this procedure after installing the driver and creating volumes,
         "elasticfilesystem:DescribeAccessPoints",
         "elasticfilesystem:DescribeFileSystems",
         "elasticfilesystem:DescribeMountTargets",
-        "ec2:DescribeAvailabilityZones"
+        "ec2:DescribeAvailabilityZones",
+        "elasticfilesystem:TagResource"
       ],
       "Resource": "*"
     },