add vendor data

vendor/golang.org/x/sys/cpu/cpu_mips64x.go

@@ -0,0 +1,15 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build mips64 || mips64le
+
+package cpu
+
+const cacheLineSize = 32
+
+func initOptions() {
+	options = []option{
+		{Name: "msa", Feature: &MIPS64X.HasMSA},
+	}
+}