KVM: Portability: Split mmu-related static inline functions to mmu.h

Since these functions need to know the details of kvm or kvm_vcpu structure,
it can't be put in x86.h.  Create mmu.h to hold them.

Signed-off-by: Zhang Xiantao <xiantao.zhang@intel.com>
Acked-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index cf78ebb..d0f431d 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -21,6 +21,7 @@
 #include "irq.h"
 #include "vmx.h"
 #include "segment_descriptor.h"
+#include "mmu.h"
 
 #include <linux/module.h>
 #include <linux/kernel.h>