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/include/dm/uclass-id.h b/include/dm/uclass-id.h
index e960e48..c3c1835 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -29,6 +29,7 @@
 	/* U-Boot uclasses start here - in alphabetical order */
 	UCLASS_ADC,		/* Analog-to-digital converter */
 	UCLASS_AHCI,		/* SATA disk controller */
+	UCLASS_AUDIO_CODEC,	/* Audio codec with control and data path */
 	UCLASS_AXI,		/* AXI bus */
 	UCLASS_BLK,		/* Block device */
 	UCLASS_BOARD,		/* Device information from hardware */