ASoC: SOF: Intel: pci-mtl: Allow DSPless mode

set the dspless_mode_supported flag to true for mtl family to allow
DSPless mode.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Link: https://lore.kernel.org/r/20230404092115.27949-11-peter.ujfalusi@linux.intel.com


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