crypto: qat - set CIPHER capability for QAT GEN2

Set the CIPHER capability for QAT GEN2 devices if the hardware supports
it. This is done if both the CIPHER and the AUTHENTICATION engines are
available on the device.

Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Marco Chiappero <marco.chiappero@intel.com>
Reviewed-by: Fiona Trahe <fiona.trahe@intel.com>
Reviewed-by: Marco Chiappero <marco.chiappero@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>