Bugfix: sound driver 'sdl' wasn't available if Bochs was compiled with SDL2 gui.
FIXME: wave output doesn't work properly in case of SDL2.


git-svn-id: svn://svn.code.sf.net/p/bochs/code/trunk@12548 6c8e4198-a580-4521-a02f-c9ae86df1db9