PCI/portdrv: Encapsulate pcie_ports_auto inside the port driver

"pcie_ports_auto" is only used inside the PCIe port driver itself, so
move it from include/linux/pci.h to portdrv.h so it's not visible to the
whole kernel.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/pcie/portdrv.h

@@ -12,6 +12,8 @@
 
 #include <linux/compiler.h>
 
+extern bool pcie_ports_auto;
+
 /* Service Type */
 #define PCIE_PORT_SERVICE_PME_SHIFT	0	/* Power Management Event */
 #define PCIE_PORT_SERVICE_PME		(1 << PCIE_PORT_SERVICE_PME_SHIFT)

include/linux/pci.h

@@ -1449,10 +1449,8 @@ static inline int pci_irqd_intx_xlate(struct irq_domain *d,
 
 #ifdef CONFIG_PCIEPORTBUS
 extern bool pcie_ports_disabled;
-extern bool pcie_ports_auto;
 #else
 #define pcie_ports_disabled	true
-#define pcie_ports_auto		false
 #endif
 
 #ifdef CONFIG_PCIEASPM