configurations: yosemite4: update fan control configs

Update fan control configs according to the test result from thermal
team.

Change-Id: I57bea4362f3e00a50ca3aaaf6706ea5167d9489a
Signed-off-by: Ricky CX Wu <ricky.cx.wu.wiwynn@gmail.com>
diff --git a/configurations/yosemite4_medusaboard_adc_rns_hsc_adi.json b/configurations/yosemite4_medusaboard_adc_rns_hsc_adi.json
index 9637a51..2b18fca 100644
--- a/configurations/yosemite4_medusaboard_adc_rns_hsc_adi.json
+++ b/configurations/yosemite4_medusaboard_adc_rns_hsc_adi.json
@@ -1849,7 +1849,7 @@
                 "MEDUSA_12VDELTA3_TEMP_C"
             ],
             "Name": "Stepwise_MEDUSA_12VDELTA",
-            "NegativeHysteresis": 3,
+            "NegativeHysteresis": 2,
             "Output": [
                 20.0,
                 22.0,