meta-ibm: only use openpower bbappend when including layer

There is a desire to add non-openpower systems to the meta-ibm layer. To
do that, need to ensure the bbappend files that are appending to
openpower recipes are only included if the machine being built includes
the meta-openpower layer.

Tested:
- Confirmed a system not including meta-openpower builds ok with this
- Confirmed p10bmc still uses the bbappend files

Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
Change-Id: I32a08e9f20a20152d51c77cdfca6bbc15b5e93d4
diff --git a/meta-ibm/conf/layer.conf b/meta-ibm/conf/layer.conf
index 763f4f5..d8478bb 100644
--- a/meta-ibm/conf/layer.conf
+++ b/meta-ibm/conf/layer.conf
@@ -8,3 +8,9 @@
 BBFILE_COLLECTIONS += "ibm-layer"
 BBFILE_PATTERN_ibm-layer := "^${LAYERDIR}/"
 LAYERSERIES_COMPAT_ibm-layer = "langdale mickledore"
+
+# Only bring in meta-openpower bbappend files if meta-openpower is
+# included in the layer
+BBFILES_DYNAMIC += "\
+    openpower-layer:${LAYERDIR}/dynamic-layers/meta-openpower/recipes-*/*/*.bbappend \
+"