readme: reminder about removing msr kernel module

Author: ppalucki

deployment/pcm/README.md

@@ -75,12 +75,17 @@ More information here: https://kubernetes.io/docs/tutorials/security/ns-level-ps
 - docker service up and running.
 - full set of metrics available only bare-metal instance or Cloud .metal instance.
 
-#### 1) (Optionally) mount resctrl filesystem (for RDT metrics)
+#### 1) (Optionally) mount resctrl filesystem (for RDT metrics) to unload "msr" kernel module for validation
 
 ```
 mount -t resctrl resctrl /sys/fs/resctrl
 ```
 
+For validation to verify that all metrics are available without msr, unload "msr" module from kernel:
+```
+rmmod msr
+```
+
 #### 2) Create kind based Kubernetes cluster
 
 ```