ethernet: T3633: Add LRO offload

[sever-sever]

Change Summary

Add LRO offload for ethernet interface.

Types of changes

• 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)

• https://phabricator.vyos.net/T3633

Component(s) name

ethernet

Proposed changes

How to test

VyOS configuration:

set interfaces ethernet eth1 offload lro
commit

Expected lro on:

vyos@r6-roll# sudo ethtool -k eth1 | grep large
large-receive-offload: on

Checklist:

• I have read the CONTRIBUTING document
• I have linked this PR to one or more Phabricator Task(s)
• I have run the components SMOKETESTS if applicable
• My commit headlines contain a valid Task id
• My change requires a change to the documentation
• I have updated the documentation accordingly