arb_texture_query_lod: relax tolerance values
requested to merge apinheiro/piglit:apinheiro/review-relax-arb-texture-query-lod-tolerance into master
This would be needed to get the test passing for v3d (mesa code still wip). The spec doesn't explicitly mention any specific precision/tolerance need, and the new tolerance values are reasonably low enough, and even smaller that tolerance values used for other texture related tests.