add norm_ffn_norm to profile script

Summary:

This PR adds an example FFN with the preceding and subsequent norms
to the profile script. I hope for this to speed up debugging of kernel
performance on LLaMa.

Test Plan:

Reviewers:

Subscribers:

Tasks:

Tags:

ghstack-source-id: 6e6036b
Pull Request resolved: #282

Author: vkuzo