Bluetooth: Fix basic debugfs entries for unconfigured controllers

When the controller is unconfigured (for example it does not have a
valid Bluetooth address), then the basic debugfs entries for dut_mode
and vendor_diag are not creates. Ensure they are created in __hci_init
and also __hci_unconf_init functions. One of them is called during setup
stage of a new controller.

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