drm/msm/dsi: use pr_err_ratelimited

When things go badly we can get a lot of these error irqs.  Let's not
DoS the user.

Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/dsi/dsi_host.c

@@ -1215,7 +1215,7 @@ static void dsi_err_worker(struct work_struct *work)
 		container_of(work, struct msm_dsi_host, err_work);
 	u32 status = msm_host->err_work_state;
 
-	pr_err("%s: status=%x\n", __func__, status);
+	pr_err_ratelimited("%s: status=%x\n", __func__, status);
 	if (status & DSI_ERR_STATE_MDP_FIFO_UNDERFLOW)
 		dsi_sw_reset_restore(msm_host);