[TRY 2] wined3d/directx.c: Corrected Nvidia 8400 and 8500 reporting

[Seth Shelnutt]

This patches moved the Nvidia 8400 and 8500 reporting to it's own if
statement and own return value. This will enable CUDA programs that check
the renderer and compare it to a list of cuda capable devices to run on
these cards. The 8300, which they currently are reported as, is not a CUDA
capable device and thus is the reason for programs such as Folding@Home to
fail in wine when using these cards.

Thanks,

Seth Shelnutt