Bluetooth: Remove enable_hs declaration

This seems to be a left-over. The module parameter enable_hs has
been removed, but its extern declaration is still present. It is
not needed anymore, so just remove it.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

include/net/bluetooth/hci.h

@@ -1787,6 +1787,4 @@ struct hci_inquiry_req {
 };
 #define IREQ_CACHE_FLUSH 0x0001
 
-extern bool enable_hs;
-
 #endif /* __HCI_H */