ec/lenovo/h8/acpi/thermal: Add ACPI fan control

Disengage the fan 10 degree below passive threshold as the automatic EC fan
control does not disengage the FAN even when CPU starts melting ...

* Add EC registers FAND and FANA.
* Add ACPI methods _AC0 and _AL0.
* Add fan device and PowerResource for fan control.

Tested on Lenovo T430:
* The fan disengages at 80°C and keeps running at full speed until temperature
  drops below 80°C.
* Fan can be disengaged using sysfs:
  /sys/devics/virtual/thermal/cooling_device0/cur_state
Tested on Lenovo T500:
* The fan disengages at 80°C and keeps running at full speed until temperature
  drops below 80°C.
* Fan cannot be disengaged using sysfs, but the current state can be read:
  /sys/devics/virtual/thermal/cooling_device0/cur_state

Change-Id: I075ff5c69676927db1c5e731294e18796884f97e
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/21227
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

0 files changed, 0 insertions, 0 deletions