ASoC: simple-card: add slot information parsing supports

For some CPU/CODEC DAI devices the slot information maybe needed. This
patch adds the slot information parsing for simple-card driver.

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/include/sound/simple_card.h b/include/sound/simple_card.h
index e1ac996..9b0ac77 100644
--- a/include/sound/simple_card.h
+++ b/include/sound/simple_card.h
@@ -18,6 +18,8 @@
 	const char *name;
 	unsigned int fmt;
 	unsigned int sysclk;
+	int slots;
+	int slot_width;
 };
 
 struct asoc_simple_card_info {