apple_smc_get_key_by_index
ret = apple_smc_get_key_by_index(smc, 0, &first_key);
ret = apple_smc_get_key_by_index(smc, smc->key_count - 1, &last_key);
ret = apple_smc_get_key_by_index(smc, pivot, &pkey);
ret = apple_smc_get_key_by_index(smcgp->smc, smcgp->first_index + i, &key);
ret = apple_smc_get_key_by_index(smc, smcgp->first_index, &key);
EXPORT_SYMBOL(apple_smc_get_key_by_index);
int apple_smc_get_key_by_index(struct apple_smc *smc, int index, smc_key *key);