PCI: add an API to get node from vector

Next patch will use the API to get the node from vector for nvme device

Signed-off-by: Shaohua Li <shli@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 282ed32..eb3da1a 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1323,6 +1323,7 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
 void pci_free_irq_vectors(struct pci_dev *dev);
 int pci_irq_vector(struct pci_dev *dev, unsigned int nr);
 const struct cpumask *pci_irq_get_affinity(struct pci_dev *pdev, int vec);
+int pci_irq_get_node(struct pci_dev *pdev, int vec);
 
 #else
 static inline int pci_msi_vec_count(struct pci_dev *dev) { return -ENOSYS; }
@@ -1370,6 +1371,11 @@ static inline const struct cpumask *pci_irq_get_affinity(struct pci_dev *pdev,
 {
 	return cpu_possible_mask;
 }
+
+static inline int pci_irq_get_node(struct pci_dev *pdev, int vec)
+{
+	return first_online_node;
+}
 #endif
 
 static inline int