PPC has a larger page size than other platforms, so increase the page
size in the test to account for this.

Change-Id: I392064e9ef3f87c5bddb7763b35661aee5b4669d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2502330
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Milad Fa <mfarazma@redhat.com>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70857}