ASoC has snd_soc_of_get_dai_link_cpus/codecs(), and these are almost same
code. The main difference are below.

	for_each_link_cpus()	dai_link->cpus		dai_link->num_cpus
	for_each_link_codecs()	dai_link->codecs	dai_link->num_codecs

Because we need to use these parameters, we can't share full-code for now,
but can share some codes.
This patch adds __snd_soc_of_get/put_xxx() functions, and share the code.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87y1xpp7ju.wl-kuninori.morimoto.gx@renesas.comSigned-off-by: Mark Brown <broonie@kernel.org>