x86: constify PCI raw ops structures

As with any other such change, the goal is to prevent inadvertent
writes to these structures (assuming DEBUG_RODATA is enabled), and to
separate data (possibly frequently) written to from such never getting
modified.

Reviewed-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/arch/x86/pci/mmconfig_64.c b/arch/x86/pci/mmconfig_64.c
index e783841..915a493 100644
--- a/arch/x86/pci/mmconfig_64.c
+++ b/arch/x86/pci/mmconfig_64.c
@@ -81,7 +81,7 @@
 	return 0;
 }
 
-static struct pci_raw_ops pci_mmcfg = {
+static const struct pci_raw_ops pci_mmcfg = {
 	.read =		pci_mmcfg_read,
 	.write =	pci_mmcfg_write,
 };