PCI/PM: Apply D2 delay as milliseconds, not microseconds

PCI_PM_D2_DELAY is defined as 200, which is milliseconds, but previously we
used udelay(), which only waited for 200 microseconds.  Use msleep()
instead so we wait the correct amount of time.  See PCIe r5.0, sec 5.9.

Link: https://lore.kernel.org/r/20191101204558.210235-2-helgaas@kernel.orgSigned-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/pci/pci.c

@@ -886,7 +886,7 @@ static int pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
 	if (state == PCI_D3hot || dev->current_state == PCI_D3hot)
 		pci_dev_d3_sleep(dev);
 	else if (state == PCI_D2 || dev->current_state == PCI_D2)
-		udelay(PCI_PM_D2_DELAY);
+		msleep(PCI_PM_D2_DELAY);
 
 	pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
 	dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);