drm/i915: Eliminate crtc->state usage from intel_update_pipe_config()

Pass the correct new crtc state to intel_update_pipe_config() instead
of using crtc->state.

Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170823152226.22938-6-ville.syrjala@linux.intel.com