cpu-o3: convert rob to new style stats

Change-Id: I84430d50c49742cd536dd75ce25184c2316dce51
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/33398
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
3 files changed