ALSA: ca0106: Support PCM sync_stop

The driver invokes snd_pcm_period_elapsed() simply from the interrupt
handler.  Set card->sync_irq for enabling the missing sync_stop PCM
operation.

Link: https://lore.kernel.org/r/20191210063454.31603-10-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/ca0106/ca0106_main.c

@@ -1638,6 +1638,7 @@ static int snd_ca0106_create(int dev, struct snd_card *card,
 		return -EBUSY;
 	}
 	chip->irq = pci->irq;
+	card->sync_irq = chip->irq;
 
 	/* This stores the periods table. */
 	if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, &pci->dev,