ALSA: wm8750: it's MONO1, not MONO

Since first commit wm8750 contained output named MONO, but
all routes mentioned MONO1. Correct MONO to be MONO1.

Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/soc/codecs/wm8750.c b/sound/soc/codecs/wm8750.c
index e23cb09..2e71394 100644
--- a/sound/soc/codecs/wm8750.c
+++ b/sound/soc/codecs/wm8750.c
@@ -348,7 +348,7 @@
 	SND_SOC_DAPM_OUTPUT("ROUT1"),
 	SND_SOC_DAPM_OUTPUT("LOUT2"),
 	SND_SOC_DAPM_OUTPUT("ROUT2"),
-	SND_SOC_DAPM_OUTPUT("MONO"),
+	SND_SOC_DAPM_OUTPUT("MONO1"),
 	SND_SOC_DAPM_OUTPUT("OUT3"),
 
 	SND_SOC_DAPM_INPUT("LINPUT1"),