cpu: log thread activate and suspend with --debug-flags Thread

The original motivation of this is to help debug syscall emulation
deadlocks.

Change-Id: I1c4f611fa2f2e464a30dc92baac89ca819e16a97
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21759
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
1 file changed