cpu: Use PCStateBase in the checker CPU.

Change-Id: I3f07e2083f803224035198b91064806991aea16e
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/52056
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabe.black@gmail.com>
2 files changed