Fix EOSPAC errors from calls in __host__ __device__ functions

[jhp-lanl]

We have been a bit lazy with our PORTABLE_INLINE_FUNCTION calls and EOSPAC. Since EOSPAC can't be called from within a device kernel, we need to get rid of those function decorators when calling EOSPAC.

For example,
https://github.com/lanl/singularity-eos/blob/main/singularity-eos/eos/eos_eospac.hpp#L1297

fails on certain platforms with the error error: reference to __host__ function 'eosSafeInterpolate' in __host__ __device__ function.

[Yurlungur]

The eospac functions need to be decorated as portable_function because of the variant. But we can implement an alternative approach to resolve this issue by clever application of preprocessor macros provided by device vendors that are only true on device.

[jhp-lanl]

Ahhhhh right... the function signature needs to be exactly the same. Sounds good!