Add /sys/devices/virtual/powercap to Masked Paths in security-conte…

…xt.md

The document does not reflect the following:
ref kubernetes/kubernetes#125970

content/en/docs/tasks/configure-pod-container/security-context.md

@@ -498,6 +498,7 @@ them. The list of masked and read-only paths are as follows:
   - `/proc/sched_debug`
   - `/proc/scsi`
   - `/sys/firmware`
+  - `/sys/devices/virtual/powercap`
 
 - Read-Only Paths:
   - `/proc/bus`
@@ -578,4 +579,4 @@ kubectl delete pod security-context-demo-4
 * Read about [User Namespaces](/docs/concepts/workloads/pods/user-namespaces/)
   for Linux pods.
 * [Masked Paths in the OCI Runtime
-  Specification](https://github.com/opencontainers/runtime-spec/blob/f66aad47309/config-linux.md#masked-paths)
+  Specification](https://github.com/opencontainers/runtime-spec/blob/f66aad47309/config-linux.md#masked-paths)