Without this string UCM cannot fetch the relevant configurations.

Fixes: b75bea4b ('ASoC: intel: sof_sdw: add rt711 rt1316 rt714 SDCA codec support')
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20201002211902.287692-3-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>