Bluetooth: Allow usb to auto-suspend when SCO use non-HCI transport

Currently usb tranport is not allowed to suspend when SCO over
HCI tranport is active.

This patch shall enable the usb tranport to suspend when SCO
link use non-HCI transport.

Signed-off-by: Chethan T N <chethan.tumkur.narayan@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>