dm: sound: Create a uclass for audio codecs

An audio codec provides a way to convert digital data to sound and vice
versa. Add a simple uclass which just supports setting the parameters for
the codec.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/sound/Makefile b/drivers/sound/Makefile
index 696c5ae..ae5fabe 100644
--- a/drivers/sound/Makefile
+++ b/drivers/sound/Makefile
@@ -4,6 +4,7 @@
 # R. Chandrasekar <rcsekar@samsung.com>
 
 obj-$(CONFIG_SOUND)	+= sound.o
+obj-$(CONFIG_DM_SOUND)	+= codec-uclass.o
 obj-$(CONFIG_I2S)	+= sound-i2s.o
 obj-$(CONFIG_I2S_SAMSUNG)	+= samsung-i2s.o
 obj-$(CONFIG_SOUND_SANDBOX)	+= sandbox.o