crypto: caam - faster aead implementation

Job descriptors only contain header and seq pointers.

Other commands are stored in separate shared descriptors
for encrypt, decrypt and givencrypt, stored as arrays
in caam_ctx.

This requires additional macros to create math commands
to calculate assoclen and cryptlen.

Signed-off-by: Yuan Kang <Yuan.Kang@freescale.com>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>