ALSA: arm: Constify snd_ac97_bus_ops definitions

Now snd_ac97_bus() takes the const ops pointer, so we can define the
snd_ac97_bus_ops locally as const as well for further optimization.

There should be no functional changes by this patch.

Link: https://lore.kernel.org/r/20200103081714.9560-25-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/arm/aaci.c

@@ -811,7 +811,7 @@ static const struct ac97_pcm ac97_defs[] = {
 	}
 };
 
-static struct snd_ac97_bus_ops aaci_bus_ops = {
+static const struct snd_ac97_bus_ops aaci_bus_ops = {
 	.write	= aaci_ac97_write,
 	.read	= aaci_ac97_read,
 };

sound/arm/pxa2xx-ac97.c

@@ -52,7 +52,7 @@ static void pxa2xx_ac97_legacy_write(struct snd_ac97 *ac97,
 	ret = pxa2xx_ac97_write(ac97->num, reg, val);
 }
 
-static struct snd_ac97_bus_ops pxa2xx_ac97_ops = {
+static const struct snd_ac97_bus_ops pxa2xx_ac97_ops = {
 	.read	= pxa2xx_ac97_legacy_read,
 	.write	= pxa2xx_ac97_legacy_write,
 	.reset	= pxa2xx_ac97_legacy_reset,