[llvm] [AMDGPU] Apply alignment attr for make.buffer.rsrc (PR #166914)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> I don't think we should put the handling of AMDGPU specific code into the generic code. We can potentially create a class inheriting the existing ones in `AMDGPUAttributor` dedicated for the handling of AMDGPU specific stuff.

AMDGPUAttributor isn't really the place for it either. It's not an AMDGPU specific attribute 

https://github.com/llvm/llvm-project/pull/166914