KVM: x86: move MTRR related code to a separate file

MTRR code locates in x86.c and mmu.c so that move them to a separate file to
make the organization more clearer and it will be the place where we fully
implement vMTRR

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 2764381..44eafdb 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -8659,7 +8659,7 @@
 		goto exit;
 	}
 
-	cache = kvm_get_guest_memory_type(vcpu, gfn);
+	cache = kvm_mtrr_get_guest_memory_type(vcpu, gfn);
 
 exit:
 	return (cache << VMX_EPT_MT_EPTE_SHIFT) | ipat;