ASoC: Intel: sof_sdw_hdmi: fix compilation issue in fallback mode

ASoC: Intel: sof_sdw_hdmi: fix compilation issue in fallback mode

Missing prefix causing build fail when NOCODEC option is selected

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20200409185827.16255-9-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>