Adding HiFi5 DSP support in Cadence backend

[dijopaul]

Summary

Add support for HiFi5 DSP build in Cadence backend
Changes are in backend/cadence folder only

Test plan

Verified the build and run locally

[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/executorch/21497

• 📄 Preview Python docs built from this PR

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⚠️ 13 Awaiting Approval

As of commit e0158e1 with merge base 761c64c ():

AWAITING APPROVAL - The following workflows need approval before CI can run:

• Build documentation (gh)
• Build Presets (gh)
• Cadence Build & Test (gh)
• Lint (gh)
• periodic (gh)
• pull (gh)
• Test ARM Backend (gh)
• Test CoreML Backend (gh)
• Test QNN Backend (gh)
• Test QNN Windows MSVC build (gh)
• Test Vulkan Backend (gh)
• Test WebGPU Backend (gh)
• Test XNNPACK Backend (gh)

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[linux-foundation-easycla]

• ❌ - login: @dijopaul / name: Dijo Paul C. The commit (e0158e1, 01ee163, 70c70f2) is not authorized under a signed CLA. Please click here to be authorized. For further assistance with EasyCLA, please visit our EasyCLA portal and chat with our support bot.

[dijopaul]

@pytorchbot label "release notes: none"