PCI/PM: Remove unused PCI_PM_BUS_WAIT

476e7fae ("PCI PM: Do not wait for buses in B2 or B3 during resume")
removed the last use of PCI_PM_BUS_WAIT.  Remove the definition as well.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/pci/pci.h

@@ -46,7 +46,6 @@ int pci_bus_error_reset(struct pci_dev *dev);
 #define PCI_PM_D2_DELAY         200
 #define PCI_PM_D3HOT_WAIT       10
 #define PCI_PM_D3COLD_WAIT      100
-#define PCI_PM_BUS_WAIT         50
 
 /**
  * struct pci_platform_pm_ops - Firmware PM callbacks