dm: video: Add a 'normal' text console driver

Most of the time we don't need to rotate the display so a simple font
blitting feature is enough for our purposes. Add a simple driver which
supports this function. It provides text output on the console using
the standard 8x16-pixel font.

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