ALSA: pci: 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/20200103081714.9560-10-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/intel8x0m.c

@@ -1079,7 +1079,7 @@ static int snd_intel8x0m_create(struct snd_card *card,
 	unsigned int i;
 	unsigned int int_sta_masks;
 	struct ichdev *ichdev;
-	static struct snd_device_ops ops = {
+	static const struct snd_device_ops ops = {
 		.dev_free =	snd_intel8x0m_dev_free,
 	};
 	static struct ich_reg_info intel_regs[2] = {