nfd, chronosync: Update

Change-Id: I651f96ef1d106d97666d0408dd12e113eba206e2
diff --git a/nfd/debian/patches/series b/nfd/debian/patches/series
new file mode 100644
index 0000000..661c3d7
--- /dev/null
+++ b/nfd/debian/patches/series
@@ -0,0 +1 @@
+downgrade-sphinx.patch