Add ODL Ansible role as a submodule

Add ODL Ansible role as a submodule

Create a TLD to store ODL-related Ansible roles, starting with the
mostly-official one used by Int/Pack's Packer build. Other community
roles can be added in the future, either directly or via submodules.

If/once the ODL Forge exists, I hope to migrate the ansible-odl Ansible
role to it, at which point we'd change the submodule pointer here to
point at that more-official repo.

Config management tools like Ansible are in-scope for Int/Pack.

wiki.opendaylight.org/view/Project_Proposals:Integration_Packaging#Scope

Change-Id: If1e621bd71fcc3e227ce8ad512bb09d251b75427
Signed-off-by: Daniel Farrell <dfarrell@redhat.com>