Fixed F' C header files to be C++ compliant.

[bdshenker]

Related Issue(s)	None
Has Unit Tests (y/n)	n
Documentation Included (y/n)	n

---

Change Description

Make affected .h files C++ compliant by adding the following construct:

#include __cplusplus
extern "C" {
#endif

// ... C-definitions

#include __cplusplus
}
#endif

Rationale

This update allows inclusion of the affected header files from C++ files.

Testing/Review Recommendations

Testing was done by running CI.
In addition these files were temporarily included from one of the C++ source files (.cpp) and FPrime was successfully rebuilt.

Future Work

None

[bdshenker]

Not sure how .h files header update caused CI to fail. Need to investigate.

[LeStarch]

Looks good to me!

[LeStarch]

Only RPI is failing, so will merge!