Unbreak Monosynth by changing listview to use a 'key' attribute instead of 'param'.

The table-edit-iface names are keys of configure variables, not real
parameters (control ports), so using the 'param' is basically incorrect.
(cherry picked from commit ab96b105e50d4de1ea423941dbc12208a997a78e)

plugins/ladspa_effect/calf/src/calf/modules_synths.h

@@ -178,6 +178,8 @@ public:
     void apply_fadeout();
     /// Main processing function
     uint32_t process(uint32_t offset, uint32_t nsamples, uint32_t inputs_mask, uint32_t outputs_mask);
+    /// Lookup of table edit interface
+    virtual table_edit_iface *get_table_edit_iface(const char *key) { if (!strcmp(key, "mod_matrix")) return static_cast<mod_matrix *>(this); else return NULL; }
 };
 
 };