File dssi-add-missing-include.patch of Package dssi

--- a/dssi/dssi.h	2009-01-09 23:41:41.000000000 +0100
+++ b/dssi/dssi.h	2024-12-28 14:45:17.639348744 +0100
@@ -24,6 +24,7 @@
 #ifndef DSSI_INCLUDED
 #define DSSI_INCLUDED
 
+#include <stddef.h>
 #include <ladspa.h>
 #include <alsa/seq_event.h>