mb/google/zork: update berknip CHTC thermal setting

Update APU CHTC thermal temperature protection point:
Temperature limit(C'): 90

Update system config=2 to meet TDP 15W design.

BUG=b:162377903
BRANCH=zork
TEST=1. emerge-zork coreboot
     2. check CHTC temperature by AMD utility

Change-Id: I03245a824d838c2d9468ae0fa3cfa34389560e9d
Signed-off-by: Kevin Chiu <kevin.chiu@quantatw.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/47158
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
diff --git a/src/mainboard/google/zork/variants/berknip/overridetree.cb b/src/mainboard/google/zork/variants/berknip/overridetree.cb
index 602b5c7..f563419 100644
--- a/src/mainboard/google/zork/variants/berknip/overridetree.cb
+++ b/src/mainboard/google/zork/variants/berknip/overridetree.cb
@@ -6,7 +6,7 @@
 	# For the below fields, 0 indicates use SOC default
 
 	# System config index
-	register "system_config" = "3"
+	register "system_config" = "2"
 
 	# Set STAPM confiuration. All of these fields must be set >0 to take affect
 	register "slow_ppt_limit_mW" = "20000"
@@ -14,6 +14,7 @@
 	register "slow_ppt_time_constant_s" = "5"
 	register "stapm_time_constant_s" = "200"
 	register "sustained_power_limit_mW" = "12000"
+	register "thermctl_limit_degreeC" = "90"
 
 	register "telemetry_vddcr_vdd_slope_mA" = "65599"
 	register "telemetry_vddcr_vdd_offset" = "0"