Update git submodules

* Update docs/submodules/releng-xci from branch 'master'
  - Merge "Combine vars setting installer type in INSTALLER_TYPE"
  - Combine vars setting installer type in INSTALLER_TYPE

    Change-Id: Ie196d1df537d09f0f91e43ab5e0305a45d543815
    Signed-off-by: Fatih Degirmenci <fdegir@gmail.com>

diff --git a/docs/submodules/releng-xci b/docs/submodules/releng-xci
index 6e31d2a..c6ea45f 160000 (submodule)
--- a/docs/submodules/releng-xci
+++ b/docs/submodules/releng-xci
@@ -1 +1 @@
-Subproject commit 6e31d2ad9e59a4a7b39fcd1e5cf21369a10fceb6
+Subproject commit c6ea45f88ce8c11e7b0e35b6d1c8cf233ebd556c