Update CMakeLists.txt for Posix GCC Demo

[kar-rahul-aws]

Description

This PR updates CMakeLists.txt to compile Posix Demo successfully, with tracing enabled.

Test Steps

cd ./FreeRTOS/FreeRTOS/Demo/Posix_GCC
cmake -B build -S .
cd build
make

Before applying the patch

FreeRTOS/Demo/Posix_GCC/./FreeRTOSConfig.h:157:14: fatal error: trcRecorder.h: No such file or directory
  157 |     #include "trcRecorder.h"
      |              ^~~~~~~~~~~~~~~

After applying the patch, it compiles successfully.

Checklist:

• I have tested my changes. No regression in existing tests.
• I have modified and/or added unit-tests to cover the code changes in this Pull Request.

Related Issue

Forum issue

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