Add support for ESN in AES-NI crypto driver

This patch adds support for IPsec ESN (Extended Sequence Numbers) in
encrypt and authenticate mode (eg. AES-CBC and SHA256) and combined mode
(eg. AES-GCM).

For the encrypt and authenticate mode the ESN is stored in separate
crp_esn buffer because the high-order 32 bits of the sequence number are
appended after the Next Header (RFC 4303).

For the combined modes the high-order 32 bits of the sequence number
[e.g. RFC 4106, Chapter 5 AAD Construction] are part of crp_aad
(prepared by netipsec layer in case of ESN support enabled), therefore
non visible diff around combined modes.

Submitted by: Grzegorz Jaszczyk <jaz@semihalf.com>

Patryk Duda <pdk@semihalf.com>

Reviewed by: jhb
Differential revision: https://reviews.freebsd.org/D22365
Obtained from: Semihalf
Sponsored by: Stormshield