Playing with very low period sizes may lead to timeouts when awaiting
RESET_STREAM reply for offload streams. This is caused by NOTIFY_POSITION
appearing in the middle of trigger(stop).

Stream is unprepared during trigger(stop) where PAUSE_STREAM IPC gets
invoked. However, all data that is already mixed in DSP firmware's mixer
stream will still be played regardless of the pause. For offload streams,
this means possibility for another NOTIFY_POSITION to process. Keep these
notifications in check by only handling them when stream is in prepared
state.

Fixes: a126750f ("ASoC: Intel: catpt: PCM operations")
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Link: https://lore.kernel.org/r/20201116133332.8530-2-cezary.rojewski@intel.comSigned-off-by: Mark Brown <broonie@kernel.org>