spdk: upgrade spdk version to 16.12

Signed-off-by: Pan Liu <pan.liu@istuary.com>

diff --git a/src/spdk b/src/spdk
index 9322c258084c6abdeefe00067f8b310a6e0d9a5a..df46c41a4ca2edabd642a73b25e54dcb173cf976 160000 (submodule)
--- a/src/spdk
+++ b/src/spdk
@@ -1 +1 @@
-Subproject commit 9322c258084c6abdeefe00067f8b310a6e0d9a5a
+Subproject commit df46c41a4ca2edabd642a73b25e54dcb173cf976