Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - Merge "Use common way to detect dpdk feature"
  - Use common way to detect dpdk feature

    Change-Id: I55a3c10f275079b11b7456b28a2c846cb33c204a
    Signed-off-by: Michael Polenchuk <mpolenchuk@mirantis.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index beab141..140f2f3 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit beab14192ba234803bf2032af6cf190dfa6b25a8
+Subproject commit 140f2f31083b58cf7bfd0900c0ad402bb13a7d7e