drm/vc4: crtc: Pass the drm_atomic_state to config_pv

The vc4_crtc_config_pv will need to access the drm_atomic_state
structure and its only parent function, vc4_crtc_atomic_enable already
has access to it. Let's pass it as a parameter.

Fixes: 792c3132 ("drm/vc4: encoder: Add finer-grained encoder callbacks")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>