i40e: reinit flow for the main VSI

This patch is the first in a 3 series patchset to implement
dynamically changing the queue count for the main VSI.

This patch starts by adding a reinit flow. This flow is designed
to be able to change just the queue count and not the number of
interrupt vectors that the device originally came up with.

Change-Id: I0634aaebf7dc4dd6c66af8f9dbbef89d7beac438
Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>