e1000e: PCIm function state support

Due to commit: 5d8682588605 ("[misc] mei: me: allow runtime
pm for platform with D0i3")
When disconnecting the cable and reconnecting it the NIC
enters DMoff state. This caused wrong link indication
and duplex mismatch. This bug is described in:
https://bugzilla.redhat.com/show_bug.cgi?id=1689436



Checking PCIm function state and performing PHY reset after a
timeout in watchdog task solves this issue.

Signed-off-by: Vitaly Lifshits <vitaly.lifshits@intel.com>
Acked-by: Sasha Neftin <sasha.neftin@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>