witherspoon: update fan-presence config

React to the configuration file format enhancements introduced
by the application.

Change-Id: I90c30c4331c70e499dafaa00e9592f2b740bd54c
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/common/recipes-phosphor/fans/phosphor-fan.bb b/common/recipes-phosphor/fans/phosphor-fan.bb
index b28271b..e70bd5b 100644
--- a/common/recipes-phosphor/fans/phosphor-fan.bb
+++ b/common/recipes-phosphor/fans/phosphor-fan.bb
@@ -37,7 +37,7 @@
 # ${PN}-presence-tach specific configuration
 PACKAGECONFIG[presence] = " \
         --enable-presence \
-        FAN_DETECT_YAML_FILE=${STAGING_DIR_NATIVE}${presence_datadir}/config.yaml, \
+        PRESENCE_CONFIG=${STAGING_DIR_NATIVE}${presence_datadir}/config.yaml, \
         --disable-presence, \
         virtual/phosphor-fan-presence-config \
         , \