Introduce a separate op implementation for get_hext_stream() for IPC4.
This op will also be used to set the skip_during_fe_trigger flag for the
BE DAI pipeline. With this change, we can remove the flag setting in
sof_ipc4_dai_config() which will further simplify support for
DMIC/SSP/Soundwire in the LunarLake platform.

Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com
Link: https://lore.kernel.org/r/20230515112022.30297-2-peter.ujfalusi@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org