sunxi: video: Add support for CSC and TVE to DE2 driver

Extend DE2 driver with support for TVE driver, which will be added in
next commit. TVE unit expects data to be in YUV format, so CSC support
is also added here.

Note that HDMI driver has higher priority, so TV out is not probed if
HDMI monitor is detected.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Simon Glass <sjg@chromium.org>