st/mesa: fix reporting of float perf counters max value

st/mesa: fix reporting of float perf counters max value

Some Piglit tests (rightfully) fail because of min >= max when exposed
to perf counters that do not explicitly define their max value.

Failing tests:
spec/amd_performance_monitor/api/test_counter_info
spec/amd_performance_monitor/vc4/test_counter_info

u32/u64 changes are no-ops.

Fixes: 4cd1cfb9831d ("st/mesa: implement GL_AMD_performance_monitor")
Signed-off-by: Marcin Ślusarz <marcin.slusarz@intel.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5473>