drm/msm: ratelimit crtc event overflow error

This can happen a lot when things go pear shaped.  Lets not flood dmesg
when this happens.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Abhinav Kumar <abhinavk@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c

@@ -389,7 +389,7 @@ static void dpu_crtc_frame_event_cb(void *data, u32 event)
 	spin_unlock_irqrestore(&dpu_crtc->spin_lock, flags);
 
 	if (!fevent) {
-		DRM_ERROR("crtc%d event %d overflow\n", crtc->base.id, event);
+		DRM_ERROR_RATELIMITED("crtc%d event %d overflow\n", crtc->base.id, event);
 		return;
 	}