drm/i915: Ensure crtc_state backpointer is always initialized

As we transition to full atomic modesetting, we want to be able to pass
intel_crtc_state around in various places that we pass intel_crtc
directly today.  Ensure that the ->crtc backpointer is properly
initialized in case we need to get back to the associated CRTC.

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -10225,6 +10225,7 @@ intel_modeset_pipe_config(struct drm_crtc *crtc,
 	if (!pipe_config)
 		return ERR_PTR(-ENOMEM);
 
+	pipe_config->base.crtc = crtc;
 	drm_mode_copy(&pipe_config->base.adjusted_mode, mode);
 	drm_mode_copy(&pipe_config->base.mode, mode);
 
@@ -12315,6 +12316,7 @@ static void intel_crtc_init(struct drm_device *dev, int pipe)
 	if (!crtc_state)
 		goto fail;
 	intel_crtc_set_state(intel_crtc, crtc_state);
+	crtc_state->base.crtc = &intel_crtc->base;
 
 	primary = intel_primary_plane_create(dev, pipe);
 	if (!primary)