meta-ibm: layer.conf: add zeus compatibility

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

(From meta-ibm rev: 9c8d1b961e1185ab2e7eabf6f6b42754fcb57db0)

Change-Id: I791f06ddb596584d1a566657a38ad6eb13692521
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-ibm/conf/layer.conf b/meta-ibm/conf/layer.conf
index 131c45b..4506bba 100644
--- a/meta-ibm/conf/layer.conf
+++ b/meta-ibm/conf/layer.conf
@@ -7,4 +7,4 @@
 
 BBFILE_COLLECTIONS += "ibm-layer"
 BBFILE_PATTERN_ibm-layer := "^${LAYERDIR}/"
-LAYERSERIES_COMPAT_ibm-layer = "thud warrior"
+LAYERSERIES_COMPAT_ibm-layer = "warrior zeus"