ASoC: fix soc-core.c kernel-doc warning

Fix a kernel-doc warning in soc-core.c by adding notation for
@legacy_dai_naming.

../sound/soc/soc-core.c:2509: warning: Function parameter or member 'legacy_dai_naming' not described in 'snd_soc_register_dai'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: alsa-devel@alsa-project.org
Link: https://lore.kernel.org/r/2215ee04-e870-5eea-a00c-9a5caf06faae@infradead.org


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