ALSA: hda - More coverage for odd-number channels elimination for HDMI

The commit ad09fc9d2156f3d37537b34418a6b79309013d33 didn't cover the
case for Intel and Nvidia HDMIs, where hdmi_pcm_open() is called.
Put the hw_constraint there, too.

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

sound/pci/hda/patch_hdmi.c

@@ -850,6 +850,9 @@ static int hdmi_pcm_open(struct hda_pcm_stream *hinfo,
 	runtime->hw.channels_max = hinfo->channels_max;
 	runtime->hw.formats = hinfo->formats;
 	runtime->hw.rates = hinfo->rates;
+
+	snd_pcm_hw_constraint_step(substream->runtime, 0,
+				   SNDRV_PCM_HW_PARAM_CHANNELS, 2);
 	return 0;
 }