crypto: qat - rename get_sla_arr_of_type()

The function get_sla_arr_of_type() returns a pointer to an SLA type
specific array.
Rename it and expose it as it will be used externally to this module.

This does not introduce any functional change.

Signed-off-by: Siming Wan <siming.wan@intel.com>
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Reviewed-by: Damian Muszynski <damian.muszynski@intel.com>
Signed-off-by: Xin Zeng <xin.zeng@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>