meta-ibm: romulus: fix file search paths

Typically it does not make any sense to append to FILESEXTRAPATHS.
FILESEXTRAPATHS is set in a bbappend when overriding something from
another layer.  The typical desire will be to make bitbake search for
files in the layer with the bbappend and not some other layer earlier in
the priority list.  Further, appending to FILESEXTRAPATHS will introduce
unexpected behavior when multiple layers append the same recipe - layers
with higher layer priorities that append to FILESEXTRAPATHS will find
their files overriden by files in layers with lower priorities.

(From meta-ibm rev: e11f36155c0fc8a6cc4bb6ef5abee777b8ae6b5a)

Change-Id: Idcd839211e009f260a38ae9cb6351154a8074c28
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-ibm/meta-romulus/recipes-phosphor/fans/phosphor-fan_%.bbappend b/meta-ibm/meta-romulus/recipes-phosphor/fans/phosphor-fan_%.bbappend
index 072623e..5c930a0 100644
--- a/meta-ibm/meta-romulus/recipes-phosphor/fans/phosphor-fan_%.bbappend
+++ b/meta-ibm/meta-romulus/recipes-phosphor/fans/phosphor-fan_%.bbappend
@@ -1,4 +1,4 @@
-FILESEXTRAPATHS_append_romulus := "${THISDIR}/${PN}:"
+FILESEXTRAPATHS_prepend_romulus := "${THISDIR}/${PN}:"
 
 # Package configuration
 FAN_PACKAGES += " \
diff --git a/meta-ibm/meta-romulus/recipes-phosphor/ipmi/phosphor-ipmi-host_%.bbappend b/meta-ibm/meta-romulus/recipes-phosphor/ipmi/phosphor-ipmi-host_%.bbappend
index d3f8431..378dab4 100644
--- a/meta-ibm/meta-romulus/recipes-phosphor/ipmi/phosphor-ipmi-host_%.bbappend
+++ b/meta-ibm/meta-romulus/recipes-phosphor/ipmi/phosphor-ipmi-host_%.bbappend
@@ -1,4 +1,4 @@
-FILESEXTRAPATHS_append_romulus := ":${THISDIR}/${PN}"
+FILESEXTRAPATHS_prepend_romulus := "${THISDIR}/${PN}:"
 SRC_URI_append_romulus = " \
     file://channel.yaml \
     "