config: chromeos: enable kselftest for coverage-enabled builds

[JenySadadia]

Replaced #1262 with this one since it needed rebase.

For now, we only run a (very) limited set of kselftests. However, enabling more of those would allow for greater code coverage. This patch creates kselftest jobs suited to running on the ChromiumOS kernel (in particular, ensuring we don't enable the ChromiumOS downstream LSM, which doesn't work with a Debian userspace).

Those tests are triggered by coverage-enabled kbuilds only, so we can eventually lower the frequency they run.

[JenySadadia]

Deployed this on staging.
All the jobs ended up with submit_error.
See https://staging.kernelci.org:9000/viewer?node_id=68df6c044ce74261cefc6cc5 and https://staging.kernelci.org:9000/viewer?node_id=68df6bee4ce74261cefc6cbc

[a-wai]

@JenySadadia IMHO the errors are a consequence of kernelci/kernelci-core@df4d46d : Lava doesn't recognize hatch as a device type, but it does recognize asus-C436FA-Flip-hatch, for instance.

@nuclearcat what motivated this change and has it been thoroughly tested?

[a-wai]

@JenySadadia Those errors should be fixed with #1329

[nuclearcat]

@nuclearcat what motivated this change and has it been thoroughly tested?

They are implemented to make qemu work, this was long standing problem and i just reimplemented it as it was in legacy KernelCI.
Obviously it was not well tested, as seems i didnt noticed that some chromebooks was broken. We will have to figure out how to detect broken devices without reviewing every of them manually.

[a-wai]

Thanks for the rebase! I finally got to curate the list of enabled tests some more and opened #1340 in order to replace this PR, hence closing.