intel/perf: fix overflow in index types

intel/perf: fix overflow in index types

With DG2, the number of perf groups and metrics climbs into the
thousands.  16bit fields are not sufficient for storing metrics
indices, and the build throws warnings when compiling the generated
intel_perf_metrics.c

Use a 32bit integer for these values.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Ivan Briano <ivan.briano@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18893>