ASoC: soc.h: clarify Codec2Codec params

snd_soc_dai_link has params/num_params, but it is unclear that
params for what. This patch clarify it is params for Codec2Codec.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87o7o5c2lk.wl-kuninori.morimoto.gx@renesas.com


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