Use DECLARE_FLEX_ARRAY() helper in include/sound/sof/control.h

[GustavoARSilva]

diff -u -p ./include/sound/sof/control.h ./include/sound/sof/control.h
--- ./include/sound/sof/control.h
+++ /tmp/nothing/include/sound/sof/control.h
@@ -117,11 +117,11 @@ struct sof_ipc_ctrl_data {
        /* control data - add new types if needed */
        union {
                /* channel values can be used by volume type controls */
                struct sof_ipc_ctrl_value_chan chanv[0];
                /* component values used by routing controls like mux, mixer */
                struct sof_ipc_ctrl_value_comp compv[0];
                /* data can be used by binary controls */
-               struct sof_abi_hdr data[0];
        };
 } __packed;