Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - Merge "[opendaylight] Support built-in DHCP service"
  - [opendaylight] Support built-in DHCP service

    Change-Id: I448aa7f076e2c2d641a5326947852b3333728460
    Signed-off-by: Michael Polenchuk <mpolenchuk@mirantis.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index 0b8c159..f0b1762 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit 0b8c15936be133c6c4aeec36d57329f862f43544
+Subproject commit f0b176221271f8441424b023edef85036c6d6af8