ASoC: SOF: sof-audio: test virtual widget in sof_walk_widgets_in_order

Virtual widgets are added for the purpose of showing connections between
aggregated DAIs in SDW topologies. However, we shouldn't touch them in
SOF.

Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20230616100039.378150-3-pierre-louis.bossart@linux.intel.com


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