crypto/qat: cleanup code

crypto/qat: cleanup code

Cleanup of unused code.
Rename and simplify a badly named struct element, was aes, but
used for all types of ciphers.
Print correct error msg (Unsupported rather than Undefined)
for all ciphers not supported by QAT PMD.

Signed-off-by: Fiona Trahe <fiona.trahe@intel.com>
Acked-by: Deepak Kumar Jain <deepak.k.jain@intel.com>