cpu: convert statistical_corrector to new style stats

Change-Id: Id9e075fb45babeeafe65105679c8bf2135823d41
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/33936
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
2 files changed