Unit test stub needed for CFE_PSP_GetKernelTextSegmentInfo

[ejtimmon]

Describe the bug
There is no unit testing stub for CFE_PSP_GetKernelTextSegmentInfo. This prevents unit testing the Checksum (CS) application.

To Reproduce
Steps to reproduce the behavior:

1. Build CS CMake Unit Tests

This produces the error "undefined reference to `CFE_PSP_GetKernelTextSegmentInfo'".

Expected behavior
Unit tests should build.

Code snips
If applicable, add references to the software.

System observed on:

• Ubuntu 18.04
• "eval-cert2" branch of the cFS repository

Reporter Info
Elizabeth Timmons/NASA GSFC