NXP backend: Enable aten.bmm with new Neutron flow.

[MartinPavella]

Summary

This PR enables the aten.bmm operator with the new Neutron MLIR flow, which removes all the past delegation restrictions. Now, all cases are supported.

Test plan

Unit tests provided.

cc @robert-kalmar @JakeStevens @digantdesai @rascani

[pytorch-bot]

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❌ 3 New Failures, 1 Cancelled Job, 2 Unrelated Failures

As of commit bfe6e5e with merge base 55c54c7 ():

NEW FAILURES - The following jobs have failed:

• pull / test-lora-multimethod-linux / linux-job (gh)
  RuntimeError: Command docker exec -t ffe09dfbb7704e6c0abfd42dcea084935e7198c03df10f0057e25b56e3b2d693 /exec failed with exit code 1
• pull / unittest / linux / linux-job (gh)
  RuntimeError: Command docker exec -t 19d50b580b23d7cf94535329b91f06f661a7bf5b33711712863bf2d8132ac583 /exec failed with exit code 1
• pull / unittest-editable / linux / linux-job (gh)
  RuntimeError: Command docker exec -t 12bea46dea5e82f01e92ca1212d1b7bd1e5c57f7dd6acb5daba243d87e2b048e /exec failed with exit code 1

CANCELLED JOB - The following job was cancelled. Please retry:

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

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

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

• pull / test-llama-runner-qnn-linux (fp32, qnn_16a16w, qnn) / linux-job (gh) (trunk failure)
• pull / unittest-editable / macos / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1

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[linux-foundation-easycla]

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[roman-janik-nxp]

LGTM, need to wait on internal tests.