drm/vc4: hdmi: Change CSC callback prototype

In order to support the YUV output, we'll need the atomic state to know
what is the state of the associated property in the CSC setup callback.

Let's change the prototype of that callback to allow us to access it.

Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>