drm/radeon: update lockup tracking when scheduling in empty ring
drm/radeon: update lockup tracking when scheduling in empty ring

From Jerome Glisse
e9273f06f28535968e40f5e58b5018d652c698d2 in ubuntu 3.8
8444d5c69549aa0f0b574cc608742d4669e1cc01 in mainline linux

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars