Bluetooth: remove header declared but not defined

hci_del_off_timer() doesn't exist anymore.
Signed-off-by: Syam Sidhardhan <s.syam@samsung.com>
Signed-off-by: Gustavo Padovan <gustavo@padovan.org>

include/net/bluetooth/hci_core.h

@@ -698,8 +698,6 @@ struct adv_entry *hci_find_adv_entry(struct hci_dev *hdev, bdaddr_t *bdaddr);
 int hci_add_adv_entry(struct hci_dev *hdev,
 					struct hci_ev_le_advertising_info *ev);
 
-void hci_del_off_timer(struct hci_dev *hdev);
-
 void hci_event_packet(struct hci_dev *hdev, struct sk_buff *skb);
 
 int hci_recv_frame(struct sk_buff *skb);