drm/omap: use DRM_ERROR_RATELIMITED() for error irqs

omapdrm uses normal DRM_ERROR() print when the HW reports an error. As
we sometimes may get a flood of errors, let's rather use
DRM_ERROR_RATELIMITED().

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/gpu/drm/omapdrm/omap_crtc.c b/drivers/gpu/drm/omapdrm/omap_crtc.c
index a4d6f5e..e91687f 100644
--- a/drivers/gpu/drm/omapdrm/omap_crtc.c
+++ b/drivers/gpu/drm/omapdrm/omap_crtc.c
@@ -261,7 +261,7 @@
 	struct omap_crtc *omap_crtc =
 			container_of(irq, struct omap_crtc, error_irq);
 	struct drm_crtc *crtc = &omap_crtc->base;
-	DRM_ERROR("%s: errors: %08x\n", omap_crtc->name, irqstatus);
+	DRM_ERROR_RATELIMITED("%s: errors: %08x\n", omap_crtc->name, irqstatus);
 	/* avoid getting in a flood, unregister the irq until next vblank */
 	__omap_irq_unregister(crtc->dev, &omap_crtc->error_irq);
 }