Update release_notes.rst

doc/release_notes.rst

@@ -78,6 +78,7 @@ controller_manager
 * Added support for the wildcard entries for the controller configuration files (`#1724 <https://github.com/ros-controls/ros2_control/pull/1724>`_).
 * The ``ros2_control_node`` node now accepts the ``thread_priority`` parameter to set the scheduler priority of the controller_manager's RT thread (`#1820 <https://github.com/ros-controls/ros2_control/pull/1820>`_).
 * The ``ros2_control_node`` node has a new ``lock_memory`` parameter to lock memory at startup to physical RAM in order to avoid page faults (`#1822 <https://github.com/ros-controls/ros2_control/pull/1822>`_).
+* The ``ros2_control_node`` node has a new ``cpu_affinity`` parameter to bind the process to a specific CPU core. By default, this is not enabled. (`#1852 <https://github.com/ros-controls/ros2_control/pull/1852>`_).
 
 hardware_interface
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