crypto: ixp4xx - check firmware for crypto support

 - the loaded firmware may not support crypto at all or
   only support DES and 3DES but not AES or
   support DES, 3DES and AES.

 - in case of no crypto support of the firmware, the module load will fail.
 - in case of missing AES support, the AES algorithms are not registered
   and a warning is printed during module load.

Signed-off-by: Christian Hohnstaedt <chohnstaedt@innominate.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>