ALSA: hda - remove controller dependency on i915 power well for SKL

For SKL, only the HDMI codec is in the display power well while the
HD-A controller isn't. So the controller flag 'need_i915_power' is
not set to release the display power after probe, and the codec flag
'link_power_control' is set to request/release the display power via
bus link_power ops.

Signed-off-by: Libin Yang <libin.yang@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 73c20c0..407978b 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -2339,7 +2339,7 @@
 	 * can cover the codec power request, and so need not set this flag.
 	 * For previous platforms, there is no such power well feature.
 	 */
-	if (is_valleyview_plus(codec))
+	if (is_valleyview_plus(codec) || is_skylake(codec))
 		codec->core.link_power_control = 1;
 
 	if (is_haswell_plus(codec) || is_valleyview_plus(codec))