NXP backend: Test max_pool2d with new Neutron flow.

[MartinPavella]

Summary

Reflect the requirements of the new Neutron MLIR flow for the max_pool2d operator in NXP backend.

Test plan

Unit tests provided.

cc @robert-kalmar @JakeStevens @digantdesai

[pytorch-bot]

🔗 Helpful Links

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✅ You can merge normally! (2 Unrelated Failures)

As of commit 7096412 with merge base 48a8d58 ():

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

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

• pull / unittest / macos / macos-job (gh) (trunk failure)
  ##[error]The operation was canceled.
• pull / unittest-editable / macos / macos-job (gh) (trunk failure)
  ##[error]The operation was canceled.

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[MartinPavella]

@novak-vaclav I am not able to add you as a reviewer, but feel free to have a look.

[novak-vaclav]

LGTM. Good work 👍

(for some reason I don't see the "Resolve comment" in the Github GUI and resolving the comments in the diff view throws "Failed to resolve thread" 🤷)

[MartinPavella]

@robert-kalmar @StrycekSimon @roman-janik-nxp could you please have a look? @novak-vaclav approved the PR already but we need an approve from someone with write access to merge.