ASoC: add for_each_card_rtds() macro

To be more readable code, this patch adds
new for_each_card_rtds() macro, and replace existing code to it.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/include/sound/soc.h b/include/sound/soc.h
index 1fffbaa..164418d 100644
--- a/include/sound/soc.h
+++ b/include/sound/soc.h
@@ -1130,6 +1130,10 @@
 #define for_each_card_links_safe(card, link, _link)			\
 	list_for_each_entry_safe(link, _link, &(card)->dai_link_list, list)
 
+#define for_each_card_rtds(card, rtd)			\
+	list_for_each_entry(rtd, &(card)->rtd_list, list)
+#define for_each_card_rtds_safe(card, rtd, _rtd)	\
+	list_for_each_entry_safe(rtd, _rtd, &(card)->rtd_list, list)
 
 /* SoC machine DAI configuration, glues a codec and cpu DAI together */
 struct snd_soc_pcm_runtime {