Change in coreboot[master]: [WIP] Nvidia Optimus support for ThinkPads

[Evgeny Zinoviev (Code Review)]

Hello Patrick Rudolph, build bot (Jenkins),

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/28380

to look at the new patch set (#8).

Change subject: [WIP] Nvidia Optimus support for ThinkPads
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[WIP] Nvidia Optimus support for ThinkPads

Based on siro's work #23041.
Tested on ThinkPad W530.

Adds ACPI code for dGPU power management.

Depends on:
https://review.coreboot.org/#/c/coreboot/+/28392
https://review.coreboot.org/#/c/coreboot/+/28393

What works (tested on 4.16.13-gentoo kernel):
- power management via _PS0 and _DSM + _PS3 ACPI calls
- nouveau driver (with a workaround, see below)
- bumblebee (from the "develop" branch)
- bbswitch
- VGA ROM loading

Known problems:
- `lspci -s 01:00.0 -vv` turns dGPU on if it was off before. Not sure why it
  happens (probably it calls _PS0 at some point) or whether it should
  happen.

Not tested yet:
- nvidia proprietary driver

Change-Id: I277808d6c1d8bd6e0a267a53f25471597698f8d5
Signed-off-by: Evgeny Zinoviev 
---
A src/drivers/lenovo/hybrid_graphics/acpi/gpu.asl
A src/drivers/nvidia/optimus/acpi/optimus.asl
A src/ec/lenovo/pmh7/acpi/pmh7.asl
M src/mainboard/lenovo/t420/acpi/ec.asl
M src/mainboard/lenovo/t420/dsdt.asl
M src/mainboard/lenovo/t420s/acpi/ec.asl
M src/mainboard/lenovo/t420s/dsdt.asl
M src/mainboard/lenovo/t430/acpi/ec.asl
M src/mainboard/lenovo/t430/dsdt.asl
M src/mainboard/lenovo/t430s/acpi/ec.asl
M src/mainboard/lenovo/t430s/dsdt.asl
M src/mainboard/lenovo/t520/acpi/ec.asl
M src/mainboard/lenovo/t520/dsdt.asl
M src/mainboard/lenovo/t530/acpi/ec.asl
M src/mainboard/lenovo/t530/dsdt.asl
M src/northbridge/intel/sandybridge/acpi/peg.asl
16 files changed, 357 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/80/28380/8