meta-aspeed: drop ASPEEDBASE

This variable is unused.  Drop.

Change-Id: I95332c3f5f6648bb5efc816772022a0e55a64972
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/conf/layer.conf b/conf/layer.conf
index 8c0d502..55ec1c8 100644
--- a/conf/layer.conf
+++ b/conf/layer.conf
@@ -8,5 +8,3 @@
 BBFILE_PATTERN_aspeed-layer := "^${LAYERDIR}/"
 LAYERVERSION_aspeed-layer = "1"
 LAYERSERIES_COMPAT_aspeed-layer = "warrior"
-
-ASPEEDBASE = '${@os.path.normpath("${LAYERDIR}/")}'