ALSA: ctxfi: Fix mono channel map to UNKNOWN

To follow the previous commit.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/ctxfi/ctpcm.c

@@ -397,23 +397,23 @@ static struct snd_pcm_ops ct_pcm_capture_ops = {
 
 static const struct snd_pcm_chmap_elem surround_map[] = {
 	{ .channels = 1,
-	  .map = { SNDRV_CHMAP_RC } },
+	  .map = { SNDRV_CHMAP_UNKNOWN } },
 	{ .channels = 2,
 	  .map = { SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
 	{ }
 };
 
 static const struct snd_pcm_chmap_elem clfe_map[] = {
 	{ .channels = 1,
-	  .map = { SNDRV_CHMAP_FC } },
+	  .map = { SNDRV_CHMAP_UNKNOWN } },
 	{ .channels = 2,
 	  .map = { SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } },
 	{ }
 };
 
 static const struct snd_pcm_chmap_elem side_map[] = {
 	{ .channels = 1,
-	  .map = { SNDRV_CHMAP_RC } },
+	  .map = { SNDRV_CHMAP_UNKNOWN } },
 	{ .channels = 2,
 	  .map = { SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
 	{ }