ALSA: pci: Constify snd_pci_quirk tables

The snd_pci_quirk tables are referred as read-only, hence they can be
declared as const gracefully.

There should be no functional changes by this patch.

Link: https://lore.kernel.org/r/20200103081714.9560-59-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/atiixp.c b/sound/pci/atiixp.c
index c3281fa..4a84073 100644
--- a/sound/pci/atiixp.c
+++ b/sound/pci/atiixp.c
@@ -282,7 +282,7 @@ static const struct pci_device_id snd_atiixp_ids[] = {
 
 MODULE_DEVICE_TABLE(pci, snd_atiixp_ids);
 
-static struct snd_pci_quirk atiixp_quirks[] = {
+static const struct snd_pci_quirk atiixp_quirks[] = {
 	SND_PCI_QUIRK(0x105b, 0x0c81, "Foxconn RC4107MA-RS2", 0),
 	SND_PCI_QUIRK(0x15bd, 0x3100, "DFI RS482", 0),
 	{ } /* terminator */