[AMDGPU][Docs] Fix broken link to HRF memory model reference (#88696)

The link to the Heterogeneous-race-free Memory Models ASPLOS'14 paper by
Hower et al. pointed to a bogus website, probably because the domain
ownership has changed.
This patch updates it to a version hosted on research.cs.wisc.edu.

Author: ritter-x2a

llvm/docs/AMDGPUUsage.rst

@@ -16024,7 +16024,7 @@ Additional Documentation
 .. [CLANG-ATTR] `Attributes in Clang <https://clang.llvm.org/docs/AttributeReference.html>`__
 .. [DWARF] `DWARF Debugging Information Format <http://dwarfstd.org/>`__
 .. [ELF] `Executable and Linkable Format (ELF) <http://www.sco.com/developers/gabi/>`__
-.. [HRF] `Heterogeneous-race-free Memory Models <http://benedictgaster.org/wp-content/uploads/2014/01/asplos269-FINAL.pdf>`__
+.. [HRF] `Heterogeneous-race-free Memory Models <https://research.cs.wisc.edu/multifacet/papers/asplos14_hrf.pdf>`__
 .. [HSA] `Heterogeneous System Architecture (HSA) Foundation <http://www.hsafoundation.com/>`__
 .. [MsgPack] `Message Pack <http://www.msgpack.org/>`__
 .. [OpenCL] `The OpenCL Specification Version 2.0 <http://www.khronos.org/registry/cl/specs/opencl-2.0.pdf>`__