[RFC] Unbound test suite from the build system

This is pretty common problem and solved well only by kselftest properly from projects I'm working on.

It is a non-trivial problem the deploy keyutils test suite to kernel test images without having to deploy also full toolchain. I've tried this a numerous times but always end up with something that is not that useful in practical use. E.g. I can with some tweaks just put Git and GNU make to the test image and with a script clone the full keyutils repository and run the tests. It sounds working solution but in practice is somewhat tedious to use.

That renders out e.g.SBC boards, which I tend to run tests but are not always online at all so in practice I can only test with QEMU/x86.

I don't have any ready made plan how to approach the detachment of the test suite but IMHO it is for the greater good that there really an issue as this limits the amount of QA that can be done for the keyutils project itself and also associated kernel features. Any feedback, ideas and proposals are welcome.