[audio] Force Cubeb to Stereo even if more than 2 channels

Force cubeb to stereo just to see if this makes any difference for EoW on Windows. Will test other changes after this.

Signed-off-by: Shinmegumi <shinmegumi@eden-emu.dev>

src/audio_core/sink/cubeb_sink.cpp

@@ -62,7 +62,7 @@ public:
             params.layout = CUBEB_LAYOUT_STEREO;
             break;
         case 6:
-            params.layout = CUBEB_LAYOUT_3F2_LFE;
+            params.layout = CUBEB_LAYOUT_STEREO;
             break;
         }