feat(s/c/tls): internal/cpu => internal/cpuproxy for arm64

I extracted and adapted this diff from 62177de
with the intent of coming up with a more manageable patch set.

The idea here is to take advantage of the cpuproxy package to use the
information it provides to better initialize crypto using arm64.

The original issue describing this problem in its full extent was
ooni/probe#1444.

We're now working to forward-port this patch to go1.17.

The current issue describing this problem as of go1.17 is
ooni/probe#1863.

Is there a better way?

src/crypto/tls/cipher_suites.go

@@ -16,6 +16,7 @@ import (
 	"fmt"
 	"hash"
 	"internal/cpu"
+	"internal/cpuproxy"
 	"runtime"
 
 	"golang.org/x/crypto/chacha20poly1305"
@@ -356,7 +357,7 @@ var defaultCipherSuitesTLS13NoAES = []uint16{
 
 var (
 	hasGCMAsmAMD64 = cpu.X86.HasAES && cpu.X86.HasPCLMULQDQ
-	hasGCMAsmARM64 = cpu.ARM64.HasAES && cpu.ARM64.HasPMULL
+	hasGCMAsmARM64 = cpuproxy.HasAES() && cpuproxy.HasGFMUL()
 	// Keep in sync with crypto/aes/cipher_s390x.go.
 	hasGCMAsmS390X = cpu.S390X.HasAES && cpu.S390X.HasAESCBC && cpu.S390X.HasAESCTR &&
 		(cpu.S390X.HasGHASH || cpu.S390X.HasAESGCM)