i40evf: report link speed

i40evf: report link speed

Orabug: 24568124

The PF driver tells us the link speed, so do something with that
information. Add link speed to log messages, and report speed through
ethtool.

Change-Id: I279dc9540cc5203376406050a3e8d67e128d5882
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
(cherry picked from commit fe458e50711b8a3dc773a6aa1f80b477991c8bbe)
Signed-off-by: Brian Maly <brian.maly@oracle.com>
Signed-off-by: Dhaval Giani <dhaval.giani@oracle.com>