ALSA: Au88x0 - Reduce the number of playback subdevices of au8830 from 32 to 16

- The maximum number of playback streams depend on the number of sample
  rate conveters (16) and the number of DMA channels (32).
Signed-off-by: Raymond Yau <superquad.vortex2@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/au88x0/au88x0.c

@@ -274,7 +274,8 @@ snd_vortex_probe(struct pci_dev *pci, const struct pci_device_id *pci_id)
 		return err;
 	}
 	// ADB pcm.
-	if ((err = snd_vortex_new_pcm(chip, VORTEX_PCM_ADB, NR_ADB)) < 0) {
+	err = snd_vortex_new_pcm(chip, VORTEX_PCM_ADB, NR_PCM);
+	if (err < 0) {
 		snd_card_free(card);
 		return err;
 	}

sound/pci/au88x0/au88x0.h

@@ -105,6 +105,7 @@
 #define MIX_SPDIF(x) (vortex->mixspdif[x])
 
 #define NR_WTPB 0x20		/* WT channels per each bank. */
+#define NR_PCM	0x10
 
 /* Structs */
 typedef struct {