You can try the API "wiced_bt_ble_scan()" and refer to its usage in the hello_client app. More information in wiced_bt_ble.h.
The EZ-Serial for CYBT-343026 doesn't support the BLE master role. So you can't find the gap_start_scan() command. If want to use a BLE master, you may need to develop your own application. You may refer to hello_client demo for reference.