PCI: expose pcie_link_speed and pcix_bus_speed arrays

pcie_link_speed and pcix_bus_speed are arrays used by probe.c to correctly
convert lnksta register values into the pci_bus_speed enum. These static arrays
are useful outside probe for this purpose. This patch makes these defines into
conist arrays and exposes them with an extern header in drivers/pci/pci.h

-v2-
* move extern declarations to drivers/pci/pci.h

CC: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 46ada5c..496c5b0 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -513,7 +513,7 @@
 	return bridge;
 }
 
-static unsigned char pcix_bus_speed[] = {
+const unsigned char pcix_bus_speed[] = {
 	PCI_SPEED_UNKNOWN,		/* 0 */
 	PCI_SPEED_66MHz_PCIX,		/* 1 */
 	PCI_SPEED_100MHz_PCIX,		/* 2 */
@@ -532,7 +532,7 @@
 	PCI_SPEED_133MHz_PCIX_533	/* F */
 };
 
-static unsigned char pcie_link_speed[] = {
+const unsigned char pcie_link_speed[] = {
 	PCI_SPEED_UNKNOWN,		/* 0 */
 	PCIE_SPEED_2_5GT,		/* 1 */
 	PCIE_SPEED_5_0GT,		/* 2 */