meta-evb: Fix warnings

 WARNING: Layer evb should set LAYERSERIES_COMPAT_evb in its
 conf/layer.conf file to list the core layer names it is compatible
 with.

 WARNING: Layer evb-aspeed should set LAYERSERIES_COMPAT_evb-aspeed in
 its conf/layer.conf file to list the core layer names it is compatible
 with.

 WARNING: Layer evb-ast2500 should set LAYERSERIES_COMPAT_evb-ast2500 in
 its conf/layer.conf file to list the core layer names it is compatible
 with.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Change-Id: I1835b6ed28e4e2d77aadbe6f328001a3ce6e68ce
diff --git a/meta-evb/conf/layer.conf b/meta-evb/conf/layer.conf
index f8f2d0e..ddb76fb 100644
--- a/meta-evb/conf/layer.conf
+++ b/meta-evb/conf/layer.conf
@@ -3,3 +3,4 @@
 
 BBFILE_COLLECTIONS += "evb"
 BBFILE_PATTERN_evb = ""
+LAYERSERIES_COMPAT_evb = "honister kirkstone"