intel/perf: repurpose INTEL_DEBUG=no-oaconfig

We initially used this debug option to mean "don't bother registering
the OA configuration into the kernel".

This change makes this option suppress any interaction with the
i915/perf interface. This is useful when debugging self modifying
batches with performance queries while running on the intel_mi_runner.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/2775>