aspeed: Append -layer to bbfile collection name

This seems to be the upstream convention.  Update to match.

Change-Id: I51557baebee8890d983d878779a5dd76ffa309be
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-ast2400/conf/layer.conf b/meta-ast2400/conf/layer.conf
index a24ac97..2ce719c 100644
--- a/meta-ast2400/conf/layer.conf
+++ b/meta-ast2400/conf/layer.conf
@@ -5,6 +5,6 @@
 BBFILES += "${LAYERDIR}/recipes-*/*/*.bb \
             ${LAYERDIR}/recipes-*/*/*.bbappend"
 
-BBFILE_PATTERN_ast2400 = "^${LAYERDIR}/"
-BBFILE_COLLECTIONS += "ast2400"
-LAYERVERSION_ast2400 = "1"
+BBFILE_PATTERN_ast2400-layer = "^${LAYERDIR}/"
+BBFILE_COLLECTIONS += "ast2400-layer"
+LAYERVERSION_ast2400-layer = "1"