Bluetooth: Add support for Add/Remove Device management commands
This allows adding or removing devices from the background scanning
list the kernel maintains. Device flagged for auto-connection will
be automatically connected if they are found.
The passive scanning required for auto-connection will be started
and stopped on demand.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>