intel/apollolake: Update gnvs for dptf

This patch updates dptf variable in gnvs based on device
configuration by reading the device tree structure.

BUG=chrome-os-partner:53096
TEST=Verify that the thermal zones are enumerated
       under /sys/class/thermal in Amenia and Reef board.
       Navigate to /sys/class/thermal, and verify that a
       thermal zone of type TCPU exists there.

Change-Id: I8ab34cdc94d8cdc840b02347569a9f07688e92cd
Signed-off-by: Shaunak Saha <shaunak.saha@intel.com>
Reviewed-on: https://review.coreboot.org/15620
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
2 files changed