guybrush: Add fan thresholds to CPU temp sensor
guybrush: Add fan thresholds to CPU temp sensor

If the SOC temp sensor fails for any reason, the CPU temp sensor should
be used as a backup to trigger the fan. Mostly guessing on thresholds
here. These values should be adjusted during thremal tuning.

BUG=b:190831599
TEST=Disable SOC sensor, see fan trigger when CPU temp reached 60
BRANCH=None

Signed-off-by: Rob Barnes <3ced0940a2329ce70499686f01d3d60685ec66ed@google.com>
Change-Id: I6f95dccd07bc588e629b8447be3149edaf2611e7
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2956830
Reviewed-by: Diana Z <cb2016afc7183e5356c690dc63b4ba817470501a@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec