fm10k: implement prepare_suspend and handle_resume

Implement fm10k_prepare_suspend and fm10k_handle_resume functions which
abstract around the now existing fm10k_prepare_for_reset and
fm10k_handle_reset. The new functions also handle stopping the service
task, which is something that the original re-init flow does not need.

Every other location that does a suspend/resume type flow is expected to
use these functions, because otherwise they may have conflicts with the
running watchdog routines. This also has the effect of preventing
possible surprise remove events during handling of FLR events and PCIe
errors.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Krishneil Singh <Krishneil.k.singh@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>