Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 5c75d372ebd4d090748c1f7cb8b1847652c6be6c
  - Merge "Doctor testing with fuel"
  - Doctor testing with fuel

    Zte pod testing fault-management
    Nokia pod testing maintenance with Fenix

    Needed by: https://gerrit.opnfv.org/gerrit/c/doctor/+/68805

    Signed-off-by: Tomi Juvonen <tomi.juvonen@nokia.com>
    Change-Id: I24f18a21ada73ae59d25b1f062320c98890b7cb4

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 368adda..5c75d37 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 368adda8beebcf81166a1a51d9190f837c6ee554
+Subproject commit 5c75d372ebd4d090748c1f7cb8b1847652c6be6c