[llvm] [AMDGPU] Drop docs for invalid load-release and store-acquire operations (PR #202338)

[via llvm-commits]

graphite-app[bot] wrote:

### Merge activity

* **Jun 9, 6:57 AM UTC**: `ritter-x2a` added this pull request to the [Graphite merge queue](https://app.graphite.com/merges?org=llvm&repo=llvm-project).


https://github.com/llvm/llvm-project/pull/202338