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_plane.c b/drivers/gpu/drm/omapdrm/omap_plane.c
index d52ff04..1c6b63f 100644
--- a/drivers/gpu/drm/omapdrm/omap_plane.c
+++ b/drivers/gpu/drm/omapdrm/omap_plane.c
@@ -357,7 +357,8 @@
 {
 	struct omap_plane *omap_plane =
 			container_of(irq, struct omap_plane, error_irq);
-	DRM_ERROR("%s: errors: %08x\n", omap_plane->name, irqstatus);
+	DRM_ERROR_RATELIMITED("%s: errors: %08x\n", omap_plane->name,
+		irqstatus);
 }
 
 static const char *plane_names[] = {