ixgbe: Move virtualization config into a separate function

This change moves the configuration that was done in configure_rx into a
separate virtualization configuration function.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>