meta-ibm: prep for new override syntax

Change-Id: I9116ed7260e369136acb39eec15075db2d4dbeba
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
diff --git a/meta-ibm/conf/machine/witherspoon.conf b/meta-ibm/conf/machine/witherspoon.conf
index 08f2935..42844c1 100644
--- a/meta-ibm/conf/machine/witherspoon.conf
+++ b/meta-ibm/conf/machine/witherspoon.conf
@@ -23,12 +23,12 @@
 PHOSPHOR_MRW_REV = "c622cb5a5dd3ebc2a4eef558d1b70740f914e6f7"
 
 # Inhibit phosphor-hwmon-config-mrw
-VIRTUAL-RUNTIME_phosphor-hwmon-config_df-mrw = ""
+VIRTUAL-RUNTIME_phosphor-hwmon-config:df-mrw = ""
 
 # Inhibit phosphor-fan-presence-mrw-native
-PREFERRED_PROVIDER_virtual/phosphor-fan-presence-config_df-mrw = \
+PREFERRED_PROVIDER_virtual/phosphor-fan-presence-config:df-mrw = \
     "phosphor-fan-presence-config"
 
 # Inhibit phosphor-fan-control-fan-config-mrw-native
-PREFERRED_PROVIDER_virtual/phosphor-fan-control-fan-config_df-mrw = \
+PREFERRED_PROVIDER_virtual/phosphor-fan-control-fan-config:df-mrw = \
     "phosphor-fan-control-fan-config"