Bluetooth: btusb: Use the cmd_timeout method to reset the Intel BT chip

If the platform provides it, use the reset gpio to reset the Intel BT
chip, as part of cmd_timeout handling. This has been found helpful on
Intel bluetooth controllers where the firmware gets stuck and the only
way out is a hard reset pin provided by the platform.

Signed-off-by: Rajat Jain <rajatja@google.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>