Clamp the latency to [256, platform default] on OSX.
Clamp the latency to [256, platform default] on OSX.

OSX allows to go lower, but a number of headsets and other hw don't work too
well with super low latency.

kinetiknz/cubeb,padenot/cubeb,padenot/cubeb,kinetiknz/cubeb,padenot/cubeb,kinetiknz/cubeb