Update git submodules

* Update docs/submodules/armband from branch 'stable/euphrates'
  - Makefile: Fix `make upgrade` from same branch

    Change-Id: I01d583995e0b557ec128111a3f5ff56684d9fb36
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>
    (cherry picked from commit 4eef836a99cd8c3c64e27adcb1e17ec5dc588116)

diff --git a/docs/submodules/armband b/docs/submodules/armband
index 779d3ab..7f54e43 160000 (submodule)
--- a/docs/submodules/armband
+++ b/docs/submodules/armband
@@ -1 +1 @@
-Subproject commit 779d3abbb1b02dc7510b058352487138b2e23f1c
+Subproject commit 7f54e431eb0c8379b3177dd79f9016fe732fbae5