add loong64 support (#106)

* fix loong64 support

* fix cacheLineSize to CacheLineSize

Co-authored-by: Xi Zhang <zhangxi@loongson.cn>

cpu/cpu_loong64.go

@@ -0,0 +1,13 @@
+// Copyright 2022 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 loong64
+// +build loong64
+
+package cpu
+
+const CacheLineSize = 64
+
+func initOptions() {
+}