meta-openpower: prep for new override syntax

Change-Id: I5ca16c6fa7bc616bfa9bc41c4f86d32fd92b0287
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
diff --git a/meta-openpower/recipes-phosphor/ipmi/phosphor-ipmi-sensor-config-native.bbappend b/meta-openpower/recipes-phosphor/ipmi/phosphor-ipmi-sensor-config-native.bbappend
index ad56a88..c584202 100644
--- a/meta-openpower/recipes-phosphor/ipmi/phosphor-ipmi-sensor-config-native.bbappend
+++ b/meta-openpower/recipes-phosphor/ipmi/phosphor-ipmi-sensor-config-native.bbappend
@@ -1 +1 @@
-OBMC_IPMI_SENSORS_PROVIDERS_append_df-openpower = " openpower-ipmi-oem-sensor-inventory-mrw-native"
+OBMC_IPMI_SENSORS_PROVIDERS:append:df-openpower = " openpower-ipmi-oem-sensor-inventory-mrw-native"