ASoC: Intel: sof_sdw: remove unused function declaration

ASoC: Intel: sof_sdw: remove unused function declaration

The functions sof_sdw_rt712_sdca_init() and sof_sdw_rt712_sdca_exit()
declared in header file are never implemented and used, remove them.

Signed-off-by: Chao Song <chao.song@linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Link: https://lore.kernel.org/r/20231127133448.18449-3-peter.ujfalusi@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>