Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - [HA] [cinder] Fix rootfs part name for sda > 2TB

    On systems with more than 2TB on /dev/sda, MaaS automatically creates
    a 1MB partition with bios_grub label as /dev/sda1.
    Account for this and expect rootfs to reside on /dev/sda2 (assume
    all compute nodes have the same behavior wrt this issue).

    Ideally, later we will switch to explicit partitioning via MaaS, or to
    a new baremetal provisioner like Ironic.

    Requires bumping Pharos git submodule to pick up the new j2 filter.

    Fixes: f6f8a56

    JIRA: FUEL-330

    Change-Id: I12f5046cf69bf2f52c8b8dc331b90048df643646
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index f6f8a56..a854b61 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit f6f8a56b40c5268d94cdb8e9aef6ea937f68a18e
+Subproject commit a854b61568c2f615672f17868e2cfe31d97c751f