crypto: atmel - add new tests to tcrypt

- set sg buffers size equals to message size
- add cfb & ofb tests for AES, DES & TDES

Signed-off-by: Nicolas Royer <nicolas@eukrea.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Eric Bénard <eric@eukrea.com>
Tested-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>