v3d: fix primitive queries for geometry shaders

v3d: fix primitive queries for geometry shaders

With geometry shaders the number of emitted primitived is decided
at run time, so we cannot precompute it in the CPU and we need to
use the PRIMITIVE_COUNTS_FEEDBACK commands to have the GPU provide
the number like we do for the number of primitives written to
transform feedback. This may have a performance impact though, since
it requires a sync wait for the draw to complete, so we only do
it when geometry shaders are present.

v2: remove '> 0' comparison for ponter type (Alejandro)

Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>