KAFKA-13671: Add ppc64le build stage

[mimaison]

Committer Checklist (excluded from commit message)

• Verify design and implementation
• Verify test coverage and CI build status
• Verify documentation (including upgrade notes)

[mimaison]

It looks like there's a permission issue with /tmp. I'm following up in KAFKA-13671.

[mimaison]

We resolved the permissions issues and it's now working. I'll let this build finish and I'll kick another one tomorrow to confirm.

[mumrah]

Thanks @mimaison, this looks good to me. Can we make the stage name something like "PPC" or "PowerPC" just for readability?

Looking at our docs, all I could find about platform support is

Kafka should run well on any unix system and has been tested on Linux and Solaris.

I wonder if we should include some details about the platforms we test. I also wonder about that Solaris part -- has anyone actually tested a recent build on Solaris?

Anyways, this PR LGTM pending a passing build, thanks 👍

[mimaison]

Thanks @mumrah! I've renamed the stage to PowerPC.
Regarding supported platforms, I'm not aware of anybody testing recent builds on Solaris. I'll follow up with a small docs PR to update that statement.

Test failures are unrelated, merging to trunk.

[ijuma]

Scala 2.12 support has been deprecated, it would be good to use Scala 2.13 for new stages.

[mimaison]

Good point, I'll follow up with a few more changes we should do in this area.