[SDL] ALSA/OSS linux audio driver priorities

[Ryan C. Gordon]

> I don't know if these are still the case...

I think those have probably been fixed by now. Also, the kernel 
developers have been pretty clear that ALSA is the way forward, and OSS 
will eventually be removed from the kernel wholesale.

That being said, in an ideal world everyone else would stop providing 
OSS wrapper layers, so SDL would only pick OSS if it's really there, and 
gracefully pick the real target instead of the real target's emulation 
layer otherwise.

In reality, I guess we'll just have to move ALSA above OSS in our 
priority list.

--ryan.