dm: video: Add a uclass for the text console

The existing LCD/video interface suffers from conflating the bitmap display
with text output on that display. As a result the implementation is more
complex than it needs to me.

We can support multiple text console drivers. Create a separate uclass to
support this, with its own API.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Anatolij Gustschin <agust@denx.de>
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 3934375..a0a3a79 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -68,6 +68,7 @@
 	UCLASS_USB_HUB,		/* USB hub */
 	UCLASS_VIDEO,		/* Video or LCD device */
 	UCLASS_VIDEO_BRIDGE,	/* Video bridge, e.g. DisplayPort to LVDS */
+	UCLASS_VIDEO_CONSOLE,	/* Text console driver for video device */
 
 	UCLASS_COUNT,
 	UCLASS_INVALID = -1,