Use EVP_has_aes_hardware to check AES-GCM hardware support.
The base::CPU logic is based on what NSS's implementation requires. BoringSSL
includes both AVX and non-AVX CLMUL code. This should make us prefer AES-GCM on
a few more CPU families; it seems PCLMULQDQ predated AVX by a year. (It's also
more correct; what we care about is not the CPU but whether BoringSSL will
enable a hardware-supported implementation.)
BUG=none
Review URL: https://codereview.chromium.org/
1217923003
Cr-Commit-Position: refs/heads/master@{#337477}