witherspoon: correct power supply derating value

The derating factor should be 90%.

Change-Id: Id67adc69f1ecd3cfb3ea083e56bb2486644d549a
Signed-off-by: Deepak Kodihalli <dkodihal@in.ibm.com>
diff --git a/obmc/sensors.py b/obmc/sensors.py
index b8c26ed..ca48525 100644
--- a/obmc/sensors.py
+++ b/obmc/sensors.py
@@ -156,7 +156,7 @@
 class PowerSupplyDeratingSensor(VirtualSensor):
     def __init__(self, bus, name):
         VirtualSensor.__init__(self, bus, name)
-        super(PowerSupplyDeratingSensor, self).setValue(10)
+        super(PowerSupplyDeratingSensor, self).setValue(90)
 
     ## override setValue method
     @dbus.service.method(