From what I know... it should be working.
Although it is a bit mysterious on Skylake yet...
On my NUC6i5SYK, I had use FakePCIID to spoof 0x9d70 as 0xa170.
On the Skylake Probook (also HDEF 0x9d70), that same spoof broke HDMI audio (so... I implemented a way to easily disable FakePCIID from ACPI as I didn't want to install different kexts for different ProBook laptops).
On my NUC6i7KYK, HDEF=0xa170 is working without any spoof (which gave the idea for the NUC6i6SYK).
Yours is 0xa170.
I guess you could try spoofing 0xa170 as 0x9d70 (simple mod to Info.plist of FakePCIID_Intel_HDMI_Audio).
Also, you might look here as syscl indicates he had to do some mods in Platforms.xml for Skylake (I tried the same thing on my NUC6i5SYK and it didn't help, which led me to the FakePCIID idea):
http://www.insanelymac.com/forum/topic/319211-guide-fix-skylake-hdmidp-output/