panfrost: allocate bo for occlusion query results

This memory needs to still be available after all the drawing is done
and forgotten about, so cannot be transient.
Also clear the result so that no rendering returns a zero.

Signed-off-by: Urja Rannikko <urjaman@gmail.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
2 files changed