ixgbe: Use pci_wake_from_d3() instead of multiple pci_enable_wake()

We were calling pci_enable_wake() twice in a row for both D3_hot
and D3_cold.  This replaces those calls with a call to pci_wake_from_d3()
to avoid issues with PCI PM vs ordering constraints.

Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>