PCI: make pci_flags always available

If we move resource assignment functions into the core, we'll still
need a way for architectures to prevent reassignment, e.g., the
"pci_probe_only" functionality, and we'll need a generic, always
available way the core can test for that.  The "pci_flags"
arrangement used by several architectures seems like a convenient
way to do this.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/setup-bus.c

@@ -25,8 +25,11 @@
 #include <linux/ioport.h>
 #include <linux/cache.h>
 #include <linux/slab.h>
+#include <asm-generic/pci-bridge.h>
 #include "pci.h"
 
+unsigned int __weak pci_flags;
+
 struct pci_dev_resource {
 	struct list_head list;
 	struct resource *res;