treewide: support yocto kirkstone release

* Deprecate N-1 release (hardknott).
* Enable N+1 release (kirkstone).

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I39e027e02dab64b4390b46ffbd9c299c858f403e
diff --git a/meta-ibm/meta-romulus/conf/layer.conf b/meta-ibm/meta-romulus/conf/layer.conf
index 3651ada..5d85212 100644
--- a/meta-ibm/meta-romulus/conf/layer.conf
+++ b/meta-ibm/meta-romulus/conf/layer.conf
@@ -7,4 +7,4 @@
 
 BBFILE_COLLECTIONS += "romulus-layer"
 BBFILE_PATTERN_romulus-layer := "^${LAYERDIR}/"
-LAYERSERIES_COMPAT_romulus-layer = "hardknott honister"
+LAYERSERIES_COMPAT_romulus-layer = "honister kirkstone"