chromeec: Add event methods for EC requested throttle

Two new events possible from the EC for starting and stopping throttle.

These are handled in a per-board method that is defined under the
thermal zone.  This is not quite where I wanted it but the scoping
rules in ACPI don't let me have a defined external object in the
same scope.

Change-Id: I766f07b4365b29df3daa8e45e88f7c38c645c287
Signed-off-by: Duncan Laurie <>
Reviewed-by: Aaron Durbin <>
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <>
2 files changed