PCI: introduce pci_is_pcie()

Introduce pci_is_pcie() which returns true if the specified PCI device
is PCI Express capable, false otherwise.

The purpose of pci_is_pcie() is removing 'is_pcie' flag in the struct
pci_dev, which is not needed because we can check it using 'pcie_cap'
field. To remove 'is_pcie', we need to update user of 'is_pcie' to use
pci_is_pcie() instead first.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

include/linux/pci.h

@@ -1317,5 +1317,16 @@ static inline int pci_pcie_cap(struct pci_dev *dev)
 	return dev->pcie_cap;
 }
 
+/**
+ * pci_is_pcie - check if the PCI device is PCI Express capable
+ * @dev: PCI device
+ *
+ * Retrun true if the PCI device is PCI Express capable, false otherwise.
+ */
+static inline bool pci_is_pcie(struct pci_dev *dev)
+{
+	return !!pci_pcie_cap(dev);
+}
+
 #endif /* __KERNEL__ */
 #endif /* LINUX_PCI_H */