i40e: move IRQ tracking setup into MSIX setup

Move the IRQ tracking setup and teardown into the same routines that
do the IRQ setup and teardown.  This keeps like activities together and
allows us to track exactly the number of vectors reserved from the OS,
which may be fewer than are available from the HW.

Change-ID: I6b2b1a955c5f0ac6b94c3084304ed0b2ea6777cf
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>