Bluetooth: ISO: Fix bcast listener cleanup

This fixes the cleanup callback for slave bis and pa sync hcons.

Closing all bis hcons will trigger BIG Terminate Sync, while closing
all bises and the pa sync hcon will also trigger PA Terminate Sync.

Signed-off-by: Iulia Tanasescu <iulia.tanasescu@nxp.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>