To add the OSC32K_CRYSTAL_INSTALLED=FALSE compilation flag
in C/C++ Compiler -> Preprocessor-> defined symbols (as the 32KHz crystal
is absent on cc2531 USB dongle).
In General Options -> target select the CC2531F256 instead of CC2530F256.
Compile and download this FW into cc2531 USB dongle. then plug it to PC,
at this point WinOS should recognize this device as CDC