ppc: fix FCTIWUZ simulation

Change-Id: Ic4c295265162f5dbc7c425d5e196a1cf2c994003
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3164978


Commit-Queue: Junliang Yan <junyan@redhat.com>
Reviewed-by: Milad Fa <mfarazma@redhat.com>
Cr-Commit-Position: refs/heads/main@{#76882}