Update git submodules

* Update docs/submodules/armband from branch 'master'
  - Armband: All local documentation builds

    Change-Id: I76b42e26375c81e9090d9d034b834f0f5b1d8506
    Signed-off-by: Trevor Bramwell <tbramwell@linuxfoundation.org>

diff --git a/docs/submodules/armband b/docs/submodules/armband
index 800e967..871ed4f 160000 (submodule)
--- a/docs/submodules/armband
+++ b/docs/submodules/armband
@@ -1 +1 @@
-Subproject commit 800e967610c003b535c6dad8289458207632d757
+Subproject commit 871ed4fbb654a31b5abda1c6ead650677287fd10