ASoC: Return error if the function does not support multi-cpu

Multi cpu is not supported by all functions yet. Add an error message
and return.

Suggested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200225133917.21314-6-yung-chuan.liao@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>