crypto: qat - remove duplicate masking for GEN6 devices

The ICP_ACCEL_CAPABILITIES_CIPHER capability is masked out redundantly
for QAT GEN6 devices.

Remove it to avoid code duplication.

This does not introduce any functional change.

Signed-off-by: Suman Kumar Chakraborty <suman.kumar.chakraborty@intel.com>
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>