ALSA: info: Make snd_info_entry_ops as const

The reference to snd_info_entry_ops is rather read-only, so declare it
as a const pointer.  This allows a bit more optimization.

There should be no functional changes by this patch.

Link: https://lore.kernel.org/r/20200103081714.9560-29-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/cs46xx/cs46xx_lib.c

@@ -2815,7 +2815,7 @@ static ssize_t snd_cs46xx_io_read(struct snd_info_entry *entry,
 	return count;
 }
 
-static struct snd_info_entry_ops snd_cs46xx_proc_io_ops = {
+static const struct snd_info_entry_ops snd_cs46xx_proc_io_ops = {
 	.read = snd_cs46xx_io_read,
 };