Modding GA-P55-USB3L (rev. 1.0) BIOS to unlock hardware passthrough

[reitso]

Motherboard's BIOS currently doesn't support booting up from PCI-E devices (NVME), so it has to be added in with a BIOS mod   v-td, even though on a hardware level, it does.
Reporting to GIGABYTE, they said: 

Hi
This board is quite old and we don't have the bios source code any more to modify.
Best Regards,
GIGABYTE

Mod needed: enabling vt-d.

I have it at its latest Bios F8, here is its save/dump: 
  BIOS DUM.rar (Size: 765.45 KB / Downloads: 3)
Latest bios update from GIGABYTE's site: 
  p55usb3l.zip (Size: 789.81 KB / Downloads: 2)