MSP430F6779 with TI-RTOS baud rate 115200 or 9600 with different MCLK

I am using MSP430F6779 with TI-RTOS and CCS 6.0 compiler. I try to run baud rate 115200 or 9600 with MCLK 23986000, the closest one to 24Mhz. The problem I run into is that UART_open always return "Error opening the UART". If I trace the code using CCS debug, I find that driver implementation function findBaudDividerIndex which search the following table can not find any entry because cpuFreq is 819200. But I have already have the following line in my .cfg file.  Can you help me how to set cpuFreq to other value so UART_open will not return any error?

Thanks.

BIOS.customCCOpts = "-vmspx --near_data=none --code_model=large --data_model=restricted -q --advice:power=1  --program_level_compile -g";
BIOS.cpuFreq.lo = 23986000;

const UARTEUSCIA_BaudrateConfig uartEUSCIABaudrates[] = {
    /* baudrate, input clock, prescalar, UCBRFx, UCBRSx, oversampling */
    {115200, 23986000, 13,   0, 0x21, 1},
    {57600, 23986000, 26,   0, 0x55, 1},
    {9600, 23986000, 156,   2, 0x6b, 1},
    {9600,   32768,   3,   0, 3, 0},
};

//////////////////UARTEUSCIA.C////////////////////////////////////////////////////////

static int32_t findBaudDividerIndex(UARTEUSCIA_BaudrateConfig const *table,
                                    uint32_t tableSize,
                                    uint32_t baudrate,
                                    uint32_t clockFreq)
{
    int32_t  index;

    Assert_isTrue((tableSize != 0) && (table != NULL), NULL);

    for (index = 0; index < tableSize; index++) {
        if ((table[index].outputBaudrate == baudrate) &&
            (table[index].inputClockFreq == clockFreq)) {
            return (index);
        }
    }
    return (-1);
}