Update git submodules

* Update docs/submodules/barometer from branch 'master'
  - Merge "ovs_pmd_stats: added ovs_pmd_stats plugin."
  - ovs_pmd_stats: added ovs_pmd_stats plugin.

    Added ovs_pmd_stats plugin which communicates with ovs-vswitch using
    unix socket and publishes pmd metrics in collectd format.

    Change-Id: I4dbdd58cdddfd13fe7df44e01c80212f2d4203fc
    Signed-off-by: Roman Korynkevych <romanx.korynkevych@intel.com>

diff --git a/docs/submodules/barometer b/docs/submodules/barometer
index a1e0e91..b8984e7 160000 (submodule)
--- a/docs/submodules/barometer
+++ b/docs/submodules/barometer
@@ -1 +1 @@
-Subproject commit a1e0e91c4ee653b5fddf71ed0108075001ba517a
+Subproject commit b8984e7fb8628b7687bd5d1d10950c889bd2d04e