Bluetooth: controller: Fix issue with duration/max number of adverts

When a maximum duration or number of advertisements has been set for an
advertisement set, we will exceed that limit if the last advertisements
happen to be overlapping (ie. we have two primary advertisements pointing
to the same AUX_ADV_IND).

We now have a check in the ticker_cb that will ignore the callback if the
state is such that advertisement would have been stopped if ull_adv_done()
had been allowed to run in the meantime.

Signed-off-by: Troels Nilsson <trnn@demant.com>