Bluetooth: Handle ADv set terminated event

This event comes after connection complete event for incoming
connections. Since we now have different random address for
each instance, conn resp address is assigned from this event.

As of now only connection part is handled as we are not
enabling duration or max num of events while starting ext adv.

Signed-off-by: Jaganath Kanakkassery <jaganathx.kanakkassery@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>