Update git submodules

* Update docs/submodules/releng-xci from branch 'master'
  - Merge "xci: Allow variable overrides from external scenarios"
  - xci: Allow variable overrides from external scenarios

    All scenarios are being cloned to XCI_SCENARIOS_CACHE so look
    there for the various override files. This will allow external
    scenarios to influence the XCI environment.

    Change-Id: I39a48ce55baaa29d09737ce6232867ef1165f099
    Signed-off-by: Markos Chandras <mchandras@suse.de>

diff --git a/docs/submodules/releng-xci b/docs/submodules/releng-xci
index 1de24fc..22c401e 160000 (submodule)
--- a/docs/submodules/releng-xci
+++ b/docs/submodules/releng-xci
@@ -1 +1 @@
-Subproject commit 1de24fc5ac68ac4857a6dfb345fa405c42ba95f1
+Subproject commit 22c401e5aed10e09b4849673f3a6bd0defbb504a