drm/vc4: Use the helper to retrieve vc4_dev when needed

We have a helper to retrieve the vc4_dev structure from the drm_device one
when needed, so let's use it consistently.
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20201029190104.2181730-4-maxime@cerno.tech

drivers/gpu/drm/vc4/vc4_hvs.c

@@ -560,7 +560,7 @@ static int vc4_hvs_bind(struct device *dev, struct device *master, void *data)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct drm_device *drm = dev_get_drvdata(master);
-	struct vc4_dev *vc4 = drm->dev_private;
+	struct vc4_dev *vc4 = to_vc4_dev(drm);
 	struct vc4_hvs *hvs = NULL;
 	int ret;
 	u32 dispctrl;
@@ -679,7 +679,7 @@ static void vc4_hvs_unbind(struct device *dev, struct device *master,
 			   void *data)
 {
 	struct drm_device *drm = dev_get_drvdata(master);
-	struct vc4_dev *vc4 = drm->dev_private;
+	struct vc4_dev *vc4 = to_vc4_dev(drm);
 	struct vc4_hvs *hvs = vc4->hvs;
 
 	if (drm_mm_node_allocated(&vc4->hvs->mitchell_netravali_filter))

drivers/gpu/drm/vc4/vc4_kms.c

@@ -51,7 +51,7 @@ static struct vc4_ctm_state *vc4_get_ctm_state(struct drm_atomic_state *state,
 					       struct drm_private_obj *manager)
 {
 	struct drm_device *dev = state->dev;
-	struct vc4_dev *vc4 = dev->dev_private;
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
 	struct drm_private_state *priv_state;
 	int ret;