Add Engram tflops

[RissyRan]

Description

Add Engram tflops calculation:

• Add matmul related flops into Engram for MFU (key/value projections are dominant)
• Didn't take Engram table building into account for "model" utilization
• Add test accordingly

Please note, this work depend on this integration PR

Tests

Expect all tests are green - link for flop_calculation_test test.

python3 -m unittest tests.unit.flop_calculation_test

Checklist

Before submitting this PR, please make sure (put X in square brackets):

• I have performed a self-review of my code. For an optional AI review, add the gemini-review label.
• I have necessary comments in my code, particularly in hard-to-understand areas.
• I have run end-to-end tests tests and provided workload links above if applicable.
• I have made or will make corresponding changes to the doc if needed, including adding new documentation pages to the relevant Table of Contents (toctree directive) as explained in our documentation.

[github-actions]

🤖 Hi @RissyRan, I've received your request, and I'm working on it now! You can track my progress in the logs for more details.

[github-actions]

🤖 I'm sorry @RissyRan, but I was unable to process your request. Please see the logs for more details.

[codecov]

Codecov Report

❌ Patch coverage is 4.54545% with 21 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/maxtext/utils/maxtext_utils.py	4.54%	21 Missing ⚠️

📢 Thoughts on this report? Let us know!