Bluetooth: Default to internal use manufacturer identifier

When allocating a new controller structure, then default to the internal
use value 0xffff first. Default to 0x0000 is a bad idea since that is
the manufacturer identifier of Ericsson Technology Licensing.

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