Bluetooth: btusb: Add support for Broadcom LM_DIAG interface
The Broadcom Bluetooth USB devices have a third interface that is
dedicated for LM_DIAG messages. The If#= 2 describes this interface
and it consists of one bulk in and one bulk endpoint.
For all Broadcom based devices with this interface, the driver now
claims it and schedules URBs for it. This allows to capture the
LM_DIAG messages and allows forwarding them via hci_recv_diag into
the diagnostic channel of the Bluetooth subsystem.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>