IVGCVSW-4775 Centralizing definition of ThreadIdSize to fix MLCE-189

* Introduce a constant definition of the size of a POSIX thread ID.
* Update all code to use the new constant definition.
* Update all unit tests to use the new constant definition.

Signed-off-by: Colm Donelan <Colm.Donelan@arm.com>
Change-Id: I836ab1a77ed13f774e66fd7b425923c24b9a6dab
diff --git a/src/profiling/ProfilingUtils.hpp b/src/profiling/ProfilingUtils.hpp
index 127534a..b9af456 100644
--- a/src/profiling/ProfilingUtils.hpp
+++ b/src/profiling/ProfilingUtils.hpp
@@ -28,6 +28,8 @@
 namespace profiling
 {
 
+constexpr unsigned int ThreadIdSize = sizeof(std::thread::id); // Is platform dependent
+
 struct SwTraceHeader
 {
     uint8_t m_StreamVersion;