Revert disabling of context tracking for Radeon (#1927)

* Revert disabling of context tracking for Radeon

Original commit 6fc228e2
 `Disable context tracking for the current version. (#1839)`

* Add env variable for disabling of context tracking for Radeon

`export NCCL_DISABLE_CONTEXT_TRACKING=1` to force disable of context tracking

* Update docs/how-to/rccl-usage-tips.rst

Fix grammar, thanks @amd-jnovotny

Co-authored-by: Jeffrey Novotny <jnovotny@amd.com>

* Rename NCCL_DISABLE_CONTEXT_TRACKING -> RCCL_DISABLE_CONTEXT_TRACKING

* Revert changes in includes and rename util function

---------

Co-authored-by: Jeffrey Novotny <jnovotny@amd.com>

docs/how-to/rccl-usage-tips.rst

@@ -253,4 +253,13 @@ set during the benchmark in the following manner:
 
 The default allreduce PyTorch benchmark peak bus bandwidth performance is
 ~170 GB/s on a single OAM with ROCm 6.2.4, while the optimized run for CPX on a
-single OAM peaks at ~315 GB/s.
+single OAM peaks at ~315 GB/s.
+
+Context tracking on Radeon GPUs
+----------------------------------------
+Context tracking is disabled on the AMD Instinct™ series of GPUs for better performance but is enabled for Radeon GPUs.
+To disable context tracking for Radeon GPUs, set the following environment variable:
+
+.. code-block:: shell
+
+   export RCCL_DISABLE_CONTEXT_TRACKING=1