crypto: caam - add support for gcm(aes)

Add support for AES working in Galois Counter Mode.

There is a limitation related to IV size, similar to the one present in
SW implementation (crypto/gcm.c):
The only IV size allowed is 12 bytes. It will be padded by HW to the right
with 0x0000_0001 (up to 16 bytes - AES block size), according to the GCM
specification.

Signed-off-by: Tudor Ambarus <tudor.ambarus@freescale.com>
Signed-off-by: Horia Geanta <horia.geanta@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>