Build 6LowPAN Contiki SubG Hz Sniffer for CC1350

Use the following steps to build 6LowPAN Contiki SubG Hz Sniffer for CC1350.
1. Go to  contiki/examples/cc2538dk/sniffer.
2. Add the followinges into project-conf.h.
    #define BOARD_CONF_DEBUGGER_DEVPACK        0
    #define PROP_MODE_CONF_SNIFFER                    1
    #define CC26XX_UART_CONF_BAUD_RATE    460800
    #define RF_CORE_CONF_CHANNEL                 25
3. make TARGET=srf06-cc26xx BOARD=srf06/cc13xx sniffer.bin.
4. Download sniffer.bin to CC1350EM and connect FT232 Serial-to-USB cable to P412 on SmartRF06EB.
5. Refer to steps here about Wireshark part.