meta-ibm: prep for new override syntax

Change-Id: I9116ed7260e369136acb39eec15075db2d4dbeba
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
diff --git a/meta-ibm/recipes-phosphor/settings/phosphor-settings-read-settings-mrw-native.bbappend b/meta-ibm/recipes-phosphor/settings/phosphor-settings-read-settings-mrw-native.bbappend
index aa8149c..debc568 100644
--- a/meta-ibm/recipes-phosphor/settings/phosphor-settings-read-settings-mrw-native.bbappend
+++ b/meta-ibm/recipes-phosphor/settings/phosphor-settings-read-settings-mrw-native.bbappend
@@ -1,2 +1,2 @@
-FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
+FILESEXTRAPATHS:prepend := "${THISDIR}/${PN}:"
 MRW_EXPRESSION_VARS = "-v PS_DERATING=${POWER_SUPPLY_DERATING_FACTOR}"