Add option to set the core affinity for the Timer Svc Task on SMP systems (#805)

Add option to set the core affinity for the Timer Svc Task on SMP systems (#805)

This PR introduces the configTIMER_SERVICE_TASK_CORE_AFFINITY option
which allows the system to configure the core affinity of the Timer
Service Task on an SMP system. The default affinity of the Timer Service
Task is set to tskNO_AFFINITY which is the current behavior on SMP
systems.

Signed-off-by: Sudeep Mohanty <sudp.mohanty@gmail.com>
Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>