meta-aspeed: 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.

Change-Id: I6a786c8f53a74b6962c7c2ea8669d0acd2babccc
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/conf/layer.conf b/conf/layer.conf
index 7e316fd..22f56a3 100644
--- a/conf/layer.conf
+++ b/conf/layer.conf
@@ -7,6 +7,6 @@
 BBFILE_COLLECTIONS += "aspeed-layer"
 BBFILE_PATTERN_aspeed-layer = ""
 LAYERVERSION_aspeed-layer = "1"
-LAYERSERIES_COMPAT_aspeed-layer = "thud"
+LAYERSERIES_COMPAT_aspeed-layer = "thud warrior"
 
 ASPEEDBASE = '${@os.path.normpath("${LAYERDIR}/")}'