radv: allow to use a compute shader for resetting the query pool

radv: allow to use a compute shader for resetting the query pool

Serious Sam Fusion 2017 uses a huge number of occlusion queries,
and the allocated query pool buffer is greater than 4096 bytes.

This slightly improves performance (tested in Ultra) from
117.2 FPS to 119.7 FPS (~+2%) on my RX480.

This also improves Talos, from 69 FPS to 72/73 FPS (~+5%).

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>