PCI / PM: Use SMART_SUSPEND and LEAVE_SUSPENDED flags for PCIe ports

Make the PCIe port driver set DPM_FLAG_SMART_SUSPEND and
DPM_FLAG_LEAVE_SUSPENDED for the devices handled by it to benefit
from the opportunistic optimizations in the PCI layer enabled by
these flags.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/pcie/portdrv_pci.c

@@ -150,6 +150,9 @@ static int pcie_portdrv_probe(struct pci_dev *dev,
 
 	pci_save_state(dev);
 
+	dev_pm_set_driver_flags(&dev->dev, DPM_FLAG_SMART_SUSPEND |
+					   DPM_FLAG_LEAVE_SUSPENDED);
+
 	if (pci_bridge_d3_possible(dev)) {
 		/*
 		 * Keep the port resumed 100ms to make sure things like