No ack() calback in component driver

[Sameer Pujar]

Hi Morimoto-san,

With your commit e2cb4a14541d ("ASoC: soc-core: merge snd_pcm_ops member 
to component driver") snd_pcm_ops is replaced with callback functions in 
component driver. In doing so, ack() callback was not retained in 
component driver.

Was this intentional because there were no users of ack() or if there 
were other reasons?

Thanks,
Sameer.