ASoC: SOF: Constify stored pointer to snd_sof_dsp_ops

The core code does not modify the 'struct snd_sof_dsp_ops', stored in
'struct sof_dev_desc'.  Make the pointer to 'struct snd_sof_dsp_ops'
const to annotate this, make code a bit safer and allow individual
drivers to also define this structure as const.

Tested-by: Pierre-Louis Bossart <[email protected]>
Signed-off-by: Krzysztof Kozlowski <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>

Author: krzk

include/sound/sof.h

@@ -166,7 +166,7 @@ struct sof_dev_desc {
 	/* default firmware name */
 	const char *default_fw_filename[SOF_IPC_TYPE_COUNT];
 
-	struct snd_sof_dsp_ops *ops;
+	const struct snd_sof_dsp_ops *ops;
 	int (*ops_init)(struct snd_sof_dev *sdev);
 	void (*ops_free)(struct snd_sof_dev *sdev);
 };