KVM: MTRR: clean up mtrr default type

Drop kvm_mtrr->enable, omit the decode/code workload and get rid of
all the hard code

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index fe9cbe4..8d43006 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -345,8 +345,7 @@
 struct kvm_mtrr {
 	struct mtrr_var_range var_ranges[KVM_NR_VAR_MTRR];
 	mtrr_type fixed_ranges[KVM_NR_FIXED_MTRR_REGION];
-	unsigned char enabled;
-	mtrr_type def_type;
+	u64 deftype;
 };
 
 struct kvm_vcpu_arch {