Support for loading SF2 on different endianness platforms.

Hi! I'm trying to get this library to work on Wii, and it would be nice if it could read in and actually byte swap if it needs to. I've been trying to patch it but got as far as this without working audio yet:

![Image](https://github.com/user-attachments/assets/f684f129-41b2-4938-bdce-a36a406a7b16)

![Image](https://github.com/user-attachments/assets/7f771494-6689-473d-988b-68391f00d6f0)