Function dcpc_create_set

* Create a fresh request set for the enablings represented in the * 'dcpc_actv_reqs' array which contains the probes we want to be * in the set. This can be called for several reasons: * * 1) We are on a single or multi overflow platform and we have no * current events so we can just create the set and initialize it. * 2) We are on a multi-overflow platform and we already have one or * more