[ez][inductor] show kernel category in kernel benchmark result (#96991)
I feel it's useful to show if an kernel is pointwise/reduction/persistent_reduction in the benchmark output. Only print the upper case of the first 3 letters to avoid wrap the line:
- POI for pointwise
- RED for reduction
- PER for persistent_reduction
<img width="1091" alt="Screenshot 2023-03-16 at 5 10 21 PM" src="https://user-images.githubusercontent.com/52589240/225780546-07b8d345-2bbe-40bd-9e65-185e9294743e.png">
Pull Request resolved: https://github.com/pytorch/pytorch/pull/96991
Approved by: https://github.com/Chillee
