Arm backend: Move corstone related build logic to util script

[AdrianLundell]

This change makes it a bit more straight forward to port the script for another platform.

• run cmake-format

[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/executorch/12993

• 📄 Preview Python docs built from this PR

Note: Links to docs will display an error until the docs builds have been completed.

❌ 2 New Failures, 1 Pending, 1 Unrelated Failure

As of commit d9ca49e with merge base 275adee ():

NEW FAILURES - The following jobs have failed:

• trunk / test-arm-cortex-m-size-test (bare_metal) / linux-job (gh)
  RuntimeError: Command docker exec -t 206d78b40cf59aa63334552b0ac4988f86c696c641e217d7a03e77010e9f727f /exec failed with exit code 1
• trunk / test-llama-runner-mac (fp32, coreml) / macos-job (gh)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1

BROKEN TRUNK - The following job failed but were present on the merge base:

👉 Rebase onto the `viable/strict` branch to avoid these failures

• trunk / test-models-macos-coreml (emformer_transcribe) / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1

This comment was automatically generated by Dr. CI and updates every 15 minutes.

[Gasoonjia]

@digantdesai

[digantdesai]

Thanks.

[zingo]

Cortex -m fails unrelated and fails without this PR

[zingo]

mac fails unrelated