ALSA: parisc: Constify snd_device_ops definitions

Now we may declare const for snd_device_ops definitions, so let's do
it for optimization.

There should be no functional changes by this patch.

Link: https://lore.kernel.org/r/20200103081714.9560-14-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/parisc/harmony.c

@@ -881,7 +881,7 @@ snd_harmony_create(struct snd_card *card,
 {
 	int err;
 	struct snd_harmony *h;
-	static struct snd_device_ops ops = {
+	static const struct snd_device_ops ops = {
 		.dev_free = snd_harmony_dev_free,
 	};