ASoC: SOF: ipc4-topology: export sof_ipc4_copier_is_single_format

We will use the sof_ipc4_copier_is_single_format() function to check if a
ipc4 copier has single format available in ipc4-pcm.c in the next patch.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Link: https://lore.kernel.org/r/20230915093507.7242-2-peter.ujfalusi@linux.intel.com


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