ASoC: SOF: ipc4-pcm: Move struct sof_ipc4_timestamp_info definition locally

The sof_ipc4_timestamp_info is only used by ipc4-pcm.c internally, it
should not be in a generic header implying that it might be used elsewhere.

Cc: stable@vger.kernel.org # 6.8
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://msgid.link/r/20240321130814.4412-12-peter.ujfalusi@linux.intel.com


Signed-off-by: Mark Brown <broonie@kernel.org>