ot::Spinel::SpinelDriver::ResetCoprocessor() method

Reset the co-processor. This method will reset the co-processor and wait until the co-process is ready (receiving SPINEL_PROP_LAST_STATUS from the it). The reset will be either a software or hardware reset. If `aSoftwareReset` is `true`, then the method will first try a software reset. If the software reset succeeds, the method exits. Otherwise the method will then try a hardware reset. If `aSoftwareReset` is `false`, then method will directly try a hardware reset.