[edn/dv] Randomly enable `regwen` in as many tests as possible

[andreaskurth]

Currently only the edn_regwen test (which is edn_smoke_test + edn_regwen_vseq, thus very simple) enables regwen. We should ideally enable regwen with a certain probability in as many of the different test cases as possible, in order to verify that it works properly. (Note that there are also automated CSR tests, which AFAIK take regwen into account, so we should only add tests for what is not covered by the automated tests.)

This will also need support from the scoreboard (in the part that predicts the effects of TL accesses).

[vogelpi]

Moving to M7 as this is more like a V3 item.