crypto: Allow GCM ciphers to have a longer IV length

GCM cipher IV length can be >=1 bytes.
When not the default 12 bytes (96 bits) sets the IV length using
`EVP_CIPHER_CTX_ctrl` with type `EVP_CTRL_GCM_SET_IVLEN`

PR-URL: https://github.com/nodejs/node/pull/6376


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Fedor Indutny <fedor.indutny@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Shigeki Ohtsu <ohtsu@iij.ad.jp>