Bluetooth: Add hook for driver to prevent wake from suspend

Let drivers have a hook to disable configuring scanning during suspend.
Drivers should use the device_may_wakeup function call to determine
whether hci should be configured for wakeup.

For example, an implementation for btusb may look like the following:

  bool btusb_prevent_wake(struct hci_dev *hdev)
  {
        struct btusb_data *data = hci_get_drvdata(hdev);
        return !device_may_wakeup(&data->udev->dev);
  }

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Reviewed-by: Alain Michaud <alainm@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>