Hi Jasonhd,
according to the screenshots you added the library correctly.
The compiler is complaining about the prototypes which are not declared.
There is a difference in default options (CW 2.10 vs CW MCU 11.x).
CW11.1 project for mpc5xxx requires function prototypes in contrast to CW 2.10. You can change this option see below:

Anyway good practice is that your .c file(s) that calls library functions should include the .h header file with function prototypes that belongs to the library.
Hope it helps.
Stan