ASoC: SOF: acpi: add dev_dbg() log for probe completion

When the probe relies on a workqueue, the completion is not signaled
by a return value. Mirror the log already present for PCI probe, so
that CI checks can test if the probe actually worked by filtering the
console logs.

Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200824200912.46852-7-pierre-louis.bossart@linux.intel.com


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