drm/sti: Use drm_crtc_vblank_*() API

Non-legacy drivers should only use this API to allow per-CRTC data to be
eventually moved into struct drm_crtc.

Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Vincent Abriou <vincent.abriou@st.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Vincent Abriou <vincent.abriou@st.com>

drivers/gpu/drm/sti/sti_hqvdp.c

@@ -763,7 +763,7 @@ static void sti_hqvdp_atomic_update(struct drm_plane *drm_plane,
 		/* Register VTG Vsync callback to handle bottom fields */
 		if (sti_vtg_register_client(hqvdp->vtg,
 					    &hqvdp->vtg_nb,
-					    mixer->id)) {
+					    crtc)) {
 			DRM_ERROR("Cannot register VTG notifier\n");
 			return;
 		}