ASoC: soc-core: move snd_soc_get_pcm_runtime()

This patch moves snd_soc_get_pcm_runtime() next to
snd_soc_get_dai_substream().
This is prepare for snd_soc_get_pcm_runtime() cleanup.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/87blshyq6e.wl-kuninori.morimoto.gx@renesas.com


Signed-off-by: Mark Brown <broonie@kernel.org>