vlib: add format pci link port

Added a function to nicely format pci link ports. Similar to the existing
link_speed etc format functions.

Type: improvement

Signed-off-by: Ray Kinsella <mdr@ashroe.eu>
Change-Id: Ic1f104e0cb34dad274f6c959e776a32c0bab697d
diff --git a/src/vlib/pci/pci.h b/src/vlib/pci/pci.h
index 5aae597..01f7d5b 100644
--- a/src/vlib/pci/pci.h
+++ b/src/vlib/pci/pci.h
@@ -325,6 +325,7 @@
 unformat_function_t unformat_vlib_pci_addr;
 format_function_t format_vlib_pci_addr;
 format_function_t format_vlib_pci_link_speed;
+format_function_t format_vlib_pci_link_port;
 format_function_t format_vlib_pci_vpd;
 
 #endif /* included_vlib_pci_h */