crypto: qat - enable rate limiting feature for GEN6 devices

Add support for enabling rate limiting(RL) feature for QAT GEN6 by
initializing the rl_data member in adf_hw_device_data structure.

Implement init_num_svc_aes() for GEN6 which will populate the number of
AEs associated with the RL service type.

Implement adf_gen6_get_svc_slice_cnt() for GEN6 which will return
the slice count that can support the RL service type.

Co-developed-by: George Abraham P <george.abraham.p@intel.com>
Signed-off-by: George Abraham P <george.abraham.p@intel.com>
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>