i40e: function to reconfigure RSS queues and rebuild

This is the second of 3 patches that allows for changing
the number of queues in the driver on the fly.

This patch adds a function that calls the reinit flow for the
main VSI after making changes to the RSS queue count as requested
by the user.

Change-Id: I82dee91e9fe90eeb4e84a7369f4b8b342155dd85
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>