T6231: MFT debs

[sempervictus]

Per comment by Nicolas Vollmar - MFT userspace tools are needed by some of the MLX functionality.

Add download and unpack directives to the OFED build script which should pull and extract the Debian package from MLX/NV's site into the current working directory which will contain the built DEBs after completion of the script for inclusion into the image build.

Testing: None yet, quickly put together to address user comment, would apperciate QA by someone who has time as i wont be able to do this until the weekend at the earliest.

Change Summary

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Code style update (formatting, renaming)
• [ ] Refactoring (no functional changes)
• [ ] Migration from an old Vyatta component to vyos-1x, please link to related PR inside obsoleted component
• [ ] Other (please describe):

Related Task(s)

Component(s) name

Proposed changes

How to test

1. Build from source
2. Deploy on system w/ CX5+ cards
3. Verify MFT tools work on the Connect-X cards.

Checklist:

• [x] I have read the CONTRIBUTING document
• [x] I have linked this PR to one or more Phabricator Task(s)
• [x] My commit headlines contain a valid Task id
• [x] My change requires a change to the documentation
• [ ] I have updated the documentation accordingly