Add UCD90160 kernel config for Witherspoon

Resolves openbmc/openbmc#653

Change-Id: I2c696ea0cf10b71ce971b456983ab0acdb5fed3f
Signed-off-by: Lei YU <mine260309@gmail.com>
diff --git a/meta-openbmc-machines/meta-openpower/meta-ibm/meta-witherspoon/recipes-kernel/linux/linux-obmc/witherspoon.cfg b/meta-openbmc-machines/meta-openpower/meta-ibm/meta-witherspoon/recipes-kernel/linux/linux-obmc/witherspoon.cfg
index 01fb1c1..45e7a1c 100644
--- a/meta-openbmc-machines/meta-openpower/meta-ibm/meta-witherspoon/recipes-kernel/linux/linux-obmc/witherspoon.cfg
+++ b/meta-openbmc-machines/meta-openpower/meta-ibm/meta-witherspoon/recipes-kernel/linux/linux-obmc/witherspoon.cfg
@@ -1,3 +1,4 @@
 CONFIG_HWMON=y
 CONFIG_SENSORS_TMP421=y
 CONFIG_SENSORS_MAX31785=y
+CONFIG_SENSORS_UCD9000=y