ALSA: hda - Disable power_save_node for IDT92HD71bxx

We've got a regression report that 4.1-rc causes noises on a Dell
laptop.  Similar like Realtek codec, this seems also triggered by the
recent power_save_node feature.  As this kind of issue is quite hard
to debug without actual hardware, disable the power_save_node flag for
this codec as a workaround.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=98971
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/patch_sigmatel.c

@@ -4696,7 +4696,8 @@ static int patch_stac92hd71bxx(struct hda_codec *codec)
 		return err;
 
 	spec = codec->spec;
-	codec->power_save_node = 1;
+	/* disabled power_save_node since it causes noises on a Dell machine */
+	/* codec->power_save_node = 1; */
 	spec->linear_tone_beep = 0;
 	spec->gen.own_eapd_ctl = 1;
 	spec->gen.power_down_unused = 1;