[llvm] [NVPTX][NFC] Use preferred LLVM coding style in NVPTX backend (PR #190572)

[Artem Belevich via llvm-commits]

Artem-B wrote:

The change itself is mostly OK, but the description is way too slop-heavy.  
It's way too verbose, and it's also out of date -- there are no UINT_MAX changes, AFAICT. The flow chart is completely out of place here, and enumerating each and every cosmetic change takes more space than the changes themselves.  
  
Please trim it down to the concise factual description of the changes. 

https://github.com/llvm/llvm-project/pull/190572