esp_pthread_set_cfg() function

- ESP_OK if configuration was successfully set - ESP_ERR_NO_MEM if out of memory - ESP_ERR_INVALID_ARG if cfg is NULL - ESP_ERR_INVALID_ARG if stack_size is less than PTHREAD_STACK_MIN - ESP_ERR_INVALID_ARG if stack_alloc_caps does not include MALLOC_CAP_8BIT

If cfg->stack_alloc_caps is 0, it is automatically set to valid default stack memory capabilities. If cfg->stack_alloc_caps is non-zero, the developer is responsible for its correctenss. This function only checks that the capabilities are MALLOC_CAP_8BIT, the rest is unchecked. Passing non-NULL attributes to pthread_create() will override the stack_size parameter set using this API