python: Fix up state tracker for sw api.
diff --git a/SConstruct b/SConstruct
index 5e171ea..606be01 100644
--- a/SConstruct
+++ b/SConstruct
@@ -124,6 +124,7 @@
 	'#/src/gallium/include',
 	'#/src/gallium/auxiliary',
 	'#/src/gallium/drivers',
+	'#/src/gallium/winsys',
 ])
 
 if env['msvc']: