dm: video: Add a driver for a rotated text console

Sometimes the console must be rotated. Add a driver which supports rotating
the text clockwise to 90, 180 and 270 degrees. This can support devices
where the display is rotated for mechanical reasons.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Anatolij Gustschin <agust@denx.de>