ALSA: ali5451: 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, as well as removing the superfluous synchronize_irq()
call.

Link: https://lore.kernel.org/r/20191210063454.31603-3-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/ali5451/ali5451.c

@@ -2026,6 +2026,7 @@ static int snd_ali_resources(struct snd_ali *codec)
 		return -EBUSY;
 	}
 	codec->irq = codec->pci->irq;
+	codec->card->sync_irq = codec->irq;
 	dev_dbg(codec->card->dev, "resources allocated.\n");
 	return 0;
 }
@@ -2099,8 +2100,6 @@ static int snd_ali_create(struct snd_card *card,
 		return -EBUSY;
 	}
 
-	synchronize_irq(pci->irq);
-
 	codec->synth.chmap = 0;
 	codec->synth.chcnt = 0;
 	codec->spdif_mask = 0;