Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "prototypes: xci: Do not require root privileges in xci-deploy"
  - prototypes: xci: Do not require root privileges in xci-deploy

    There is no good reason to run the script as root. If elevated
    privileges are required then we will do it on a per case basis.

    Change-Id: I7195fb3a0026ea20ce04e0b652dd3c1c56ca5741
    Signed-off-by: Markos Chandras <mchandras@suse.de>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 93c0193..42b51b5 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 93c01936bbd57752820bcf22078c8268677dafe1
+Subproject commit 42b51b59fa7271731cc09995c1355db4e9ac426c