[AE/osxsink] - handle AE_FMT_FLOATP in scorestream

Fixes no matching stream was found with airplay devices as audio output.

I think this is for gotham as well
This might be a bit confusing for folk who don't understand how it works maybe.  A comment along the lines of "if we get float, regardless of planar or not, prefer the highest bitdepth.  For streams that are non-planar we let AE know in Initialize()"