[Benchmarking]: Changes to bench files w.r.t scaling factor (#1083)

This `PR` : 
- updates the `batch` used in the benchmarks to `512` as it helps in
better scaling for `avx2` targets,
- adds new set of `avx2` benchmarks targeting `ARLs` `P` and `E` cores
separately,
- as `ARL` has no flag in `lscpu` to get it distinguished, we use
`cpuid` logic to trigger benchmarks targeted to `ARL`.

Author: arun-thmn