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/common.c b/arch/x86/pci/common.c
index 92df322..7962ccb 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -33,8 +33,8 @@
 int pcibios_last_bus = -1;
 unsigned long pirq_table_addr;
 struct pci_bus *pci_root_bus;
-struct pci_raw_ops *raw_pci_ops;
-struct pci_raw_ops *raw_pci_ext_ops;
+const struct pci_raw_ops *__read_mostly raw_pci_ops;
+const struct pci_raw_ops *__read_mostly raw_pci_ext_ops;
 
 int raw_pci_read(unsigned int domain, unsigned int bus, unsigned int devfn,
 						int reg, int len, u32 *val)