[llvm] [AMDGPU] Use llvm::find and llvm::find_if (NFC) (PR #135582)

[Jakub Kuderski via llvm-commits]

kuhar wrote:

> What is the benefit of doing this?

The range functions are more concise and you can't accidentally pass in iterators from two different containers. This is an NFC.

https://github.com/llvm/llvm-project/pull/135582