Bluetooth: Introduce unconfigured controller state

With the new unconfigured controller state it is possible to provide a
fully functional HCI transport, but disable the higher level operations
that would normally happen. This way userspace can try to configure the
controller before releases the unconfigured state.

The internal state is represented by HCI_UNCONFIGURED. This replaces the
HCI_QUIRK_RAW_DEVICE quirk as internal state representation. This is now
a real state and drivers can use the quirk to actually trigger this
state. In the future this will allow a more fine grained switching from
unconfigured state to configured state for controller inititialization.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>