It's this will be work?
// Initialize the Bond Manager.
bond_init_data.flash_page_num_bond = FLASH_PAGE_BOND;
bond_init_data.flash_page_num_sys_attr = FLASH_PAGE_SYS_ATTR;
bond_init_data.evt_handler = bond_evt_handler;
bond_init_data.error_handler = bond_manager_error_handler;
bond_init_data.bonds_delete = true;
err_code = ble_bondmngr_init(&bond_init_data);