Stress test that was validating thread safeness was configured to use
higher sys tick rate and targeting qemu_x86 platform. However, it was
also build for other platforms and was failing. Fixing it by extracting
stress tests to separate configuration that is run only on qemu_x86.
Modified the test to fail when number of preemptions is less than
expected only on qemu_x86.
Signed-off-by: Krzysztof Chruscinski <krzysztof.chruscinski@nordicsemi.no>
Added test cases that validates if ring buffer handles
correctly case with single producer single consumer from
different contexts.
Signed-off-by: Krzysztof Chruscinski <krzysztof.chruscinski@nordicsemi.no>
