ASoC: SOF: topology: Constify struct snd_soc_tplg_ops

Constifying "struct snd_soc_tplg_ops" moves some data to a read-only
section, so increase overall security.

On a x86_64, with allmodconfig:
Before:
   text	   data	    bss	    dec	    hex	filename
  44519	   2888	     48	  47455	   b95f	sound/soc/sof/topology.o

After:
   text	   data	    bss	    dec	    hex	filename
  44839	   2552	     48	  47439	   b94f	sound/soc/sof/topology.o
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://msgid.link/r/2d9f5b75e979eb38b6f3baf85dfa1f0fdb3447ef.1715526069.git.christophe.jaillet@wanadoo.frSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/topology.c

@@ -2278,7 +2278,7 @@ static const struct snd_soc_tplg_bytes_ext_ops sof_bytes_ext_ops[] = {
 	{SOF_TPLG_KCTL_BYTES_VOLATILE_RO, snd_sof_bytes_ext_volatile_get},
 };
 
-static struct snd_soc_tplg_ops sof_tplg_ops = {
+static const struct snd_soc_tplg_ops sof_tplg_ops = {
 	/* external kcontrol init - used for any driver specific init */
 	.control_load	= sof_control_load,
 	.control_unload	= sof_control_unload,
@@ -2433,7 +2433,7 @@ static int sof_dspless_link_load(struct snd_soc_component *scomp, int index,
 	return 0;
 }
 
-static struct snd_soc_tplg_ops sof_dspless_tplg_ops = {
+static const struct snd_soc_tplg_ops sof_dspless_tplg_ops = {
 	/* external widget init - used for any driver specific init */
 	.widget_ready	= sof_dspless_widget_ready,
 	.widget_unload	= sof_dspless_widget_unload,