enable ASPM

Hello everybody!
I’ve got a HP EliteBook 8570w, i7 IvyBridge + NVIDIA Quadro K2000M (as relevant).
It’s now been quite long time since I started trying to get ASPM enabled in order to set hybrid graphics, and be able to switch off discrete NVIDIA GPU and start using Intel HDx000, which is integrated in the CPU.
Now, for some reason nobody at HP knows, there is no way to turn on ASPM through the BIOS utility (I’m using UEFI btw). I asked them for help twice, with no satisfactory response. The point is, as far as I understand, ACPI tables are in charge of telling the kernel about the hardware capabilities, actually

dmesg | grep ASPM


acpi PNP0A08:00: Disabling ASPM (FADT indicates it is unsupported)
, however I was able to turn it on just temporarily with


The question is: Is there a way to override de FACP/FADT acpi table? (I know it’s possible to do it to a DSDT table but I think the procedure is not exactly the same).
If not: Is there any other way to do it? (Modifying the BIOS is 90% discarded, as it’s RSA signed).
All suggestions will be appreciated.
Thanks in advance!