Add s390x to build automation

[Joshua-Beha]

What type of PR is this?

What this PR does / why we need it:
This PR adds building the s390x image to the current build automation. Currently, the build automation is only for amd64 and arm.
Which issue(s) this PR fixes (optional, using fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when the PR gets merged):
Fixes #
#1683

Special notes for your reviewer:

TODOs:

• [ x] squashed commits
• includes documentation
• adds unit tests

[linux-foundation-easycla]

• ✅login: Joshua-Beha / (43d7a0b)

The committers listed above are authorized under a signed CLA.

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: Joshua-Beha
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[k8s-ci-robot]

Hi @Joshua-Beha. Thanks for your PR.

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