Bluetooth: Remove __hci_dev_put/hold

Since we remove the owner field of hci_dev hci_dev_put and __hci_dev_put
do the same so we can merge them into one function. Same for
hci_dev_hold and __hci_dev_hold.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>