LM3S support in vsprog

Information:
    Vsprog can support LM3S in JTAG/SWD interfaces.
    Auto-detect feature is supported on LM3S.
    Supported target area: flash('f').

Vsprog options:
    -slm3s, refer to -s option.
    -c, refer to -c option.
    -m, refer to -m option. Supported modes:
        j: JTAG mode, default
        s: SWD mode
    -F, refer to -F option. This option is only valid in JTAG mode, default is 12000 / 6, unit: kHz.
    -W, refer to -W option. This option is only valid in SWD mode, default is 0. It defines the speed of SWD, the lower the value the faster the speed. Normally, default value is OK.
    -x, refer to -x option.