Automatic merge from submit-queue (batch tested with PRs 60455, 61365, 61375, 61597, 61491). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Fix help text for cpu manager
**What this PR does / why we need it**:
Fixes incorrect text associated with the flag as the feature is now beta.
**Special notes for your reviewer**:
This feature is beta in 1.10.
**Release note**:
```release-note
NONE
```