meta-ibm: layer.conf: Add warrior compatibility

oe-core branched in preparation for the upcoming 2.7 Yocto release and
as of 13e45ff requires core layer compatibility to "warrior" instead of
"thud".  We'll retain compatibility for both until we do our own branch
or stop testing thud.

(From meta-ibm rev: 97893b2c0bf39cfaee58ccfc4f85249f9a1d8abf)

Change-Id: I2e772add384637011a80acf52861b88ac71be98b
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-ibm/conf/layer.conf b/meta-ibm/conf/layer.conf
index fd05fc4..2d1bdcf 100644
--- a/meta-ibm/conf/layer.conf
+++ b/meta-ibm/conf/layer.conf
@@ -7,7 +7,7 @@
 
 BBFILE_COLLECTIONS += "ibm-layer"
 BBFILE_PATTERN_ibm-layer = ""
-LAYERSERIES_COMPAT_ibm-layer = "thud"
+LAYERSERIES_COMPAT_ibm-layer = "thud warrior"
 
 # Provide a variable that points the base of the ibm layer.
 IBMBASE = '${@os.path.normpath("${LAYERDIR}/")}'