s390/pci: s390 specific PCI sysfs attributes

Add some s390 specific sysfs attributes to the PCI device directory.
The following attributes are introduced:
- function_id (PCI function ID)
- function_handle (PCI function handle)
- pchid (PCI channel ID)
- pfgid (PCI function group ID aka PCI root complex)

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/pci.h

@@ -141,6 +141,10 @@ struct zpci_dev *get_zdev(struct pci_dev *);
 struct zpci_dev *get_zdev_by_fid(u32);
 bool zpci_fid_present(u32);
 
+/* sysfs */
+int zpci_sysfs_add_device(struct device *);
+void zpci_sysfs_remove_device(struct device *);
+
 /* DMA */
 int zpci_dma_init(void);
 void zpci_dma_exit(void);