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>