PCI: Fix build if quirks are not enabled

After commit b9c3b266411d27f1a6466c19d146d08db576bfea ("PCI: support
device-specific reset methods") the kernel build is broken if
CONFIG_PCI_QUIRKS is unset.

Fix this by moving pci_dev_specific_reset() to drivers/pci/quirks.c and
providing an empty replacement for !CONFIG_PCI_QUIRKS builds.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 709eaa4..fbd0e3a 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -319,6 +319,6 @@
 	int (*reset)(struct pci_dev *dev, int probe);
 };
 
-extern struct pci_dev_reset_methods pci_dev_reset_methods[];
+extern int pci_dev_specific_reset(struct pci_dev *dev, int probe);
 
 #endif /* DRIVERS_PCI_H */