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-openpower/conf/layer.conf b/meta-openpower/conf/layer.conf
index 9a16ca0..7f17f30 100644
--- a/meta-openpower/conf/layer.conf
+++ b/meta-openpower/conf/layer.conf
@@ -9,4 +9,4 @@
 BBFILE_PATTERN_openpower-layer := "^${LAYERDIR}/"
 LAYERVERSION_openpower-layer = "1"
 LAYERDEPENDS_openpower-layer = "core phosphor-layer aspeed-layer"
-LAYERSERIES_COMPAT_openpower-layer = "hardknott honister"
+LAYERSERIES_COMPAT_openpower-layer = "honister kirkstone"