Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - Update release notes for 6.2

    Change-Id: Ibd168ef31af1f8a9a2c128ce8a8e95a5c231a917
    Signed-off-by: Cristina Pauna <cristina.pauna@enea.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index d151d43..ea9cf53 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit d151d4342aa828e0f4c94e7390262080686fcfa3
+Subproject commit ea9cf5304b649298c40155714a4374724aec1835