arch-riscv: added dummy implementation of wfi instruction.

Change-Id: I7ca86f57c7d794bf544e34e747875049a3f29d6a
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25653
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Gem5 Cloud Project GCB service account <345032938727@cloudbuild.gserviceaccount.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
1 file changed