Automatic merge from submit-queue (batch tested with PRs 60983, 62012, 61892, 62051, 62067). 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>.

kubeadm: Controllable timeout for join failures

**What this PR does / why we need it**:

This PR introduces a timeout for `kubeadm join`. During that time kubeadm will try to join as many times as possible. The timeout can be controlled via the `discoveryTimeout` config option. Its default value is 5 minutes.

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes kubernetes/kubeadm#677

**Special notes for your reviewer**:

/cc @kubernetes/sig-cluster-lifecycle-pr-reviews
/area kubeadm
/assign @luxas
/assign @timothysc

**Release note**:

```release-note
kubeadm: Introduce join timeout that can be controlled via the discoveryTimeout config option (set to 5 minutes by default).
```