Bluetooth: audio: has: Fix sending notifications on reconnect

This fixes missing setting of FLAG_CONTROL_POINT_NOTIFY flag that
indicate whether submit control_point_work. In case the there are more
indications/notifications to sent (is_last flag is unset), the
FLAG_CONTROL_POINT_NOTIFY shall be set to resubmit control_point_work.

Signed-off-by: Mariusz Skamra <mariusz.skamra@codecoup.pl>