i40e: use functions to enable and disable icr 0

Introduce i40e_irq_dynamic_disable_icr0 and use it and its previously-
extant counterpart when appropriate.

Change-Id: Ieb4037874fba2e96fc2354b34a97a3cb8f6490f3
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Tested-by: Sibai Li <sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>