[ROCm] Update C++ Extension Tutorial for AMD GPU (#3197)

* Update C++ Extension tutorial with note about AMD GPU.
---------

Co-authored-by: Svetlana Karslioglu <[email protected]>

Author: naromero77amd

advanced_source/cpp_extension.rst

@@ -1207,3 +1207,5 @@ examples displayed in this note `here
 <https://github.com/pytorch/extension-cpp>`_. If you have questions, please use
 `the forums <https://discuss.pytorch.org>`_. Also be sure to check our `FAQ
 <https://pytorch.org/cppdocs/notes/faq.html>`_ in case you run into any issues.
+A blog on writing extensions for AMD ROCm can be found `here
+<https://rocm.blogs.amd.com/artificial-intelligence/cpp-extn/readme.html>`_.