KVM: Add kvm_x86_ops get_tdp_level()

The function get_tdp_level() provided the number of tdp level for EPT and
NPT rather than the NPT specific macro.

Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

include/asm-x86/kvm_host.h

@@ -422,6 +422,7 @@ struct kvm_x86_ops {
 				       struct kvm_run *run);
 
 	int (*set_tss_addr)(struct kvm *kvm, unsigned int addr);
+	int (*get_tdp_level)(void);
 };
 
 extern struct kvm_x86_ops *kvm_x86_ops;