ASoC: soc-core: merge soc_new_pcm_runtime() and soc_rtd_init()

ASoC: soc-core: merge soc_new_pcm_runtime() and soc_rtd_init()

"rtd"      is handled by soc_xxx_pcm_runtime(), and
"rtd->dev" is handled by soc_rtd_xxx().

There is no reason to separate these, and it makes code complex.
We can create these in the same time.

This patch merges soc_rtd_init() into soc_new_pcm_runtime().

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87a7baf7pz.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>