Use ARMv8 CRC32 instructions for SkOpts::hash().

src/opts/SkOpts_crc32.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkOpts.h"
 
-#define SK_OPTS_NS sse42
+#define SK_OPTS_NS crc32
 #include "SkChecksum_opts.h"
 
 namespace SkOpts {
-    void Init_sse42() {
-        hash_fn = sse42::hash_fn;
+    void Init_crc32() {
+        hash_fn = crc32::hash_fn;
     }
 }
-