st,ir3,radeonsi: push lower_deref_instrs back into driver

st,ir3,radeonsi: push lower_deref_instrs back into driver

vc4+vc5 is not really effected by the deref chain to deref instr
conversion, so it no longer needs this pass.  For others, now that
all the passes mesa/st uses are using deref instructions, push the
lowering to deref chains back into driver.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Acked-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>