Bluetooth: Fix SMP channel registration for unconfigured controllers

When the Bluetooth controllers requires an unconfigured state (for
example when the BD_ADDR is missing), then it is important to try
to register the SMP channels when the controller transitions to the
configured state.

This also fixes an issue with the debugfs entires that are not present
for controllers that start out as unconfigured.

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