Update git submodules

Update git submodules

* Update docs/submodules/multicloud/k8s.git from branch 'master'
  to 672d736a054ddffaecd2910a8171844fddc38bdd
  - Merge "Update single-node KUD installation variables"
  - Update single-node KUD installation variables

    Single host installation requires some kubespray variables defined
    differently from what is currently defined by default. All-in-one
    installation script has been updated to provide these differences.
    CI-building script has been updated and removed applying variables
    there, as it's not specific just for CI, but for every single-node
    installation.

    Issue-ID: MULTICLOUD-1093
    Signed-off-by: Konrad Bańka <k.banka@samsung.com>
    Change-Id: I26c1835d87df41c087b8dfff9f52095083b6c160