Bluetooth: Host: Fix missing term callback for PA syncs

When deleting a PA sync with bt_le_per_adv_sync_delete
Zephyr should call the `term` callback for the PA sync
as per the documentation for the callback.

This was not done in the case that the PA sync was
terminated by local request.

Signed-off-by: Emil Gydesen <emil.gydesen@nordicsemi.no>