i40e: Disable link polling

i40e: Disable link polling

Orabug: 23176970

Periodic link polling was added when the link events were found not to be
trustworthy.  This was the case early on, but was likely because the link
event mask was being used incorrectly.  As this has been fixed in recent
code, we can disable the link polling to lessen the AQ traffic.

Change-ID: Id890b5ee3c2d04381fc76ffa434777644f5d8eb0
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
(cherry picked from commit 8c806b676d21a49628250731f4e30a8a071d080c)
Signed-off-by: Brian Maly <brian.maly@oracle.com>