Remove final csp instances, missed in the earlier patch due to being outside
the arm64 tree.

Bug: v8:6644
Change-Id: I2b5a2716568949740991c368b64c0a06105e4ff2
Reviewed-on: https://chromium-review.googlesource.com/874310Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Martyn Capewell <martyn.capewell@arm.com>
Cr-Commit-Position: refs/heads/master@{#50698}