ASoC: Add multiple CPU DAI support in DAPM

DAPM handles DAIs during soc_dapm_stream_event() and during addition
and creation of DAI widgets i.e., dapm_add_valid_dai_widget() and
dapm_connect_dai_link_widgets().

Extend these functions to handle multiple cpu dai.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Shreyas NC <shreyas.nc@intel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20200225133917.21314-5-yung-chuan.liao@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>