PCI/LINK: Print IRQ number used by port

Print the IRQ used by PCIe Link Bandwidth Notification services port as
AER, PME and DPC do.  It provides convenience to track PCIe BW notification
interrupt counts of certain port from /proc/interrupts.

The dmesg log is as below:

  pcieport 0000:00:00.0: bw_notification: enabled with IRQ 1166

Link: https://lore.kernel.org/r/1599737055-73624-1-git-send-email-liudongdong3@huawei.comSigned-off-by: NDongdong Liu <liudongdong3@huawei.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

drivers/pci/pcie/bw_notification.c

@@ -14,6 +14,8 @@
  * and warns when links become degraded in operation.
  */
 
+#define dev_fmt(fmt) "bw_notification: " fmt
+
 #include "../pci.h"
 #include "portdrv.h"
 
@@ -97,6 +99,7 @@ static int pcie_bandwidth_notification_probe(struct pcie_device *srv)
 		return ret;
 
 	pcie_enable_link_bandwidth_notification(srv->port);
+	pci_info(srv->port, "enabled with IRQ %d\n", srv->irq);
 
 	return 0;
 }