meta-phosphor: layer.conf: add zeus compatibility

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

Change-Id: I9ce9f58cf7d67a9b1757734784ebdf879bdf8193
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/conf/layer.conf b/conf/layer.conf
index 764afde..d352306 100644
--- a/conf/layer.conf
+++ b/conf/layer.conf
@@ -8,7 +8,7 @@
 BBFILE_COLLECTIONS += "phosphor-layer"
 BBFILE_PATTERN_phosphor-layer := "^${LAYERDIR}/"
 LAYERVERSION_phosphor-layer = "1"
-LAYERSERIES_COMPAT_phosphor-layer = "thud warrior"
+LAYERSERIES_COMPAT_phosphor-layer = "warrior zeus"
 
 IMAGE_FEATURES[validitems] += "tools-profile"