dm: cros_ec: Add support for driver model

Add support for driver model if enabled. This involves minimal changes
to the code, mostly just plumbing around the edges.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index c92adb4..0ea7a6f 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -26,6 +26,7 @@
 	UCLASS_SPI,		/* SPI bus */
 	UCLASS_SPI_GENERIC,	/* Generic SPI flash target */
 	UCLASS_SPI_FLASH,	/* SPI flash */
+	UCLASS_CROS_EC,	/* Chrome OS EC */
 
 	UCLASS_COUNT,
 	UCLASS_INVALID = -1,