yocto:mickledore: add support for new yocto layer

Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
Change-Id: I8e54833ac78e540e9dd5011533d53ff9a3af6763
diff --git a/meta-ampere/meta-mitchell/conf/layer.conf b/meta-ampere/meta-mitchell/conf/layer.conf
index 3855afb..8f58810 100644
--- a/meta-ampere/meta-mitchell/conf/layer.conf
+++ b/meta-ampere/meta-mitchell/conf/layer.conf
@@ -7,5 +7,5 @@
 
 BBFILE_COLLECTIONS += "mitchell-layer"
 BBFILE_PATTERN_mitchell-layer := "^${LAYERDIR}/"
-LAYERSERIES_COMPAT_mitchell-layer = "kirkstone langdale"
+LAYERSERIES_COMPAT_mitchell-layer = "langdale mickledore"