fm10k: disable service task during suspend

The service task reads some registers as part of its normal routine,
even while the interface is down. Normally this is ok. However, during
suspend we have disabled the PCI device. Due to this, registers will
read in the same way as a surprise-remove event. Disable the service
task while we suspend, and re-enable it after we resume. If we don't do
this, the device could be UP when you suspend and come back from resume
as closed (since fm10k closes the device when it gets a surprise
remove).

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>