add langdale to compatible layer

Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
Change-Id: I65febeeec11e6e5b40ee728f42cfbe77023dae1e
diff --git a/meta-openpower/conf/layer.conf b/meta-openpower/conf/layer.conf
index 7f17f30..ef36835 100644
--- a/meta-openpower/conf/layer.conf
+++ b/meta-openpower/conf/layer.conf
@@ -9,4 +9,4 @@
 BBFILE_PATTERN_openpower-layer := "^${LAYERDIR}/"
 LAYERVERSION_openpower-layer = "1"
 LAYERDEPENDS_openpower-layer = "core phosphor-layer aspeed-layer"
-LAYERSERIES_COMPAT_openpower-layer = "honister kirkstone"
+LAYERSERIES_COMPAT_openpower-layer = "kirkstone langdale"