Add missing backslash in package list

Change-Id: I3763694ac68d044f26be49e6c06e6422fe4df4e4
diff --git a/rootfs-packages.mk b/rootfs-packages.mk
index e92c822..506df4a 100644
--- a/rootfs-packages.mk
+++ b/rootfs-packages.mk
@@ -20,7 +20,7 @@
     base-files \
     bluetooth \
     bluez \
-    libbluetooth3
+    libbluetooth3 \
     mdt-services \
     mendel-distro-info-data \
     mendel-keyring \