We will add a section for "cpufreq" Collector in "nodeExporter.collectors" section in CMO configmap. 

It has a boolean field "enabled" , default value is false.

apiVersion: v1
kind: ConfigMap
metadata: 
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data: 

  config.yaml: |

    nodeExporter: 
      collectors: 
        # enable a collector which is disabled by default
        cpufreq: 
          enabled: true

Before implementing this feature, check the metrics from this collector is not necessary for alerts and dashboards.