crypto: inside-secure - authenc(hmac(sha256), cbc(aes)) support

This patch adds support for the first AEAD algorithm in the Inside
Secure SafeXcel driver, authenc(hmac(sha256),cbc(aes)). As this is the
first AEAD algorithm added to this driver, common AEAD functions are
added as well.

Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>