meta-openpower: layer.conf add zeus compatibility

OE-Core master will be dropping warrior soon; zeus is the next release.

(From meta-openpower rev: 919b020895d59ef129695aba0b26245db6cf8ad2)

Change-Id: I03090f096d4dec31d15d4ddcabe78b42e8ebe8b9
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-openpower/conf/layer.conf b/meta-openpower/conf/layer.conf
index 2cb27d2..7b3028f 100644
--- a/meta-openpower/conf/layer.conf
+++ b/meta-openpower/conf/layer.conf
@@ -8,4 +8,4 @@
 BBFILE_COLLECTIONS += "openpower-layer"
 BBFILE_PATTERN_openpower-layer := "^${LAYERDIR}/"
 LAYERVERSION_openpower-layer = "1"
-LAYERSERIES_COMPAT_openpower-layer = "thud warrior"
+LAYERSERIES_COMPAT_openpower-layer = "warrior zeus"