freedreno/ir3: move atomic fixup after RA

A post-RA sched pass will move the extra mov's to the wrong place, so
rework the fixup so it can run after RA (and therefore after postsched)

Signed-off-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3569>
3 files changed