Bluetooth: Handle Intel USB bootloader with buggy interrupt

The interrupt interface for the Intel USB bootloader devices is only
enabled after receiving SetInterface(0, AltSetting=0). When this USB
command is not send, then no HCI events will be received.

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