freedreno: make hw-query a helper

freedreno: make hw-query a helper

For a5xx (and actually some queries on a4xx) we can accumulate results
in the cmdstream, so we don't need this elaborate mechanism of tracking
per-tile query results.  So make it into vfuncs so generation specific
backend can use it when it makes sense.

Signed-off-by: Rob Clark <robdclark@gmail.com>