freedreno/ir3: also track # of nops for shader-db

freedreno/ir3: also track # of nops for shader-db

The instruction count is (mostly) a measure of what optimization passes
can do, while # of nops is more an indication of how effectively the
scheduler is balancing register pressure vs instruction count.  So track
these independently.

(There could be opportunities to rematerialize values to reduce register
pressure, swapping some nop's with other alu instructions, so nothing is
truely independent.. but it is still useful to break these stats out.)

Signed-off-by: Rob Clark <robdclark@chromium.org>