tests: rtio: rtio_api: test cq_count overflow

[JordanYates]

Add a test for the behaviour of rtio_submit with CONFIG_RTIO_SUBMIT_SEM=n when the cq_count variable overflows.

Note CI is currently expected to fail, this is a POC of the behaviour.

[teburd]

Test makes sense to me.

I guess to fix this we will need to correct the compare to understand a rollover may be required, we can do that by perhaps tracking not just the needed (and potentially rolled over count) but by tracking the the starting count and the difference in count we need to wait on.

E.g. maybe something like this?

uintptr_t cq_start_count = atomic_get(...);
bool wraps = (cq_start_count + wait_count) < cq_start_count; /* wrapping! */
while (atomic_get(...) >= (cq_start_count + wait_count) && wraps) {
}
while ( atomic_get(...) < (cq_start_count + wait_count) ) {
}

I'm open to suggestions

[JordanYates]

Incorporated in #85079