ASoC: soc-card: add snd_soc_card_to_dapm()

ASoC: soc-card: add snd_soc_card_to_dapm()

Because struct snd_soc_dapm_context is soc-dapm framework specific, user
driver don't need to access its member directly, we would like to hide
them. struct snd_soc_dapm_context will be removed from header in the
future.

Current dapm of card/component are using "instance", but it will be
"pointer" if snd_soc_dapm_context was removed from header.

snd_soc_card_to_dapm() is needed to switch to the new style while
maintaining compatibility

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://patch.msgid.link/877byex06i.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>