i40e/i40evf: add tracking to NVM busy state

The NVM updates take some time and are asynchronous actions that signal
their completion with an AdminQ event.  This code tracks when there is
an NVM update outstanding and won't allow a new update command until a
completion event is received from the current update.

Change-ID: Ic132fe16bd9dc09b002ed38297a877c1a01553ce
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Acked-by: Mitch Williams <mitch.a.williams@intel.com>
Acked-by: Greg Rose <gregory.v.rose@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>