ASoC: sdw_utils: split asoc_sdw_get_codec_name

ASoC: sdw_utils: split asoc_sdw_get_codec_name

Currently asoc_sdw_get_codec_name will return codec_info->codec_name if
it is set. However, in some case we need the sdw codec name no matter if
codec_info->codec_name is set or not.
_asoc_sdw_get_codec_name() will be used in the follow up commit.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Link: https://patch.msgid.link/20250414063239.85200-11-yung-chuan.liao@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>