output_queue allows the Xtensa to push data on a queue
which the device needs to implement.
With the full method the Xtensa CPU might ask if the queue
is currently full or not.
To data method is used to push data on the output queue
of the device. out_data is a pointer to the pushed data
and bit_width how many bits that is pushed on the queue.
If reserve_only is true, no data is present but the device
should just allocate space for the data.