ASoC: n810: Use snd_pcm_hw_constraint_single()

Use the new snd_pcm_hw_constraint_single() helper function instead of
calling snd_pcm_hw_constraint_minmax() with the same value for min and max
to install a constraint that limits the possible configuration values to a
single value. Using snd_pcm_hw_constraint_single() makes the indented
result clearer and is slightly shorter.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Acked-by: NJarkko Nikula <jarkko.nikula@bitmer.com>
Acked-by: NMark Brown <broonie@kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

sound/soc/omap/n810.c

@@ -99,8 +99,7 @@ static int n810_startup(struct snd_pcm_substream *substream)
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 
-	snd_pcm_hw_constraint_minmax(runtime,
-				     SNDRV_PCM_HW_PARAM_CHANNELS, 2, 2);
+	snd_pcm_hw_constraint_single(runtime, SNDRV_PCM_HW_PARAM_CHANNELS, 2);
 
 	n810_ext_control(&rtd->card->dapm);
 	return clk_prepare_enable(sys_clkout2);