drm/tegra: dc: Wire up CRTC parent of atomic state

Store a pointer to the CRTC in its atomic state to make it easy for
state handling code to get at the CRTC.

Tested-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
index ec84bd4..2fd2293 100644
--- a/drivers/gpu/drm/tegra/dc.c
+++ b/drivers/gpu/drm/tegra/dc.c
@@ -997,8 +997,10 @@
 	crtc->state = NULL;
 
 	state = kzalloc(sizeof(*state), GFP_KERNEL);
-	if (state)
+	if (state) {
 		crtc->state = &state->base;
+		crtc->state->crtc = crtc;
+	}
 }
 
 static struct drm_crtc_state *