change hil s3 baudarte

[hathach]

Describe the PR
lower flashing baudrate for hil s3, since it seems to have stable issue with pi5 + cp2102

[378571.099339] usb 1-2.1.2: device descriptor read/8, error -71
[378571.234364] usb 1-2.1.2: device descriptor read/8, error -71
[378571.345366] usb 1-2.1-port2: unable to enumerate USB device
[378571.942508] cp210x ttyUSB0: failed to get comm status: -71
[378571.944417] cp210x ttyUSB0: failed set request 0x7 status: -71
[378571.946412] cp210x ttyUSB0: failed set request 0x12 status: -71
[378571.948422] cp210x ttyUSB0: failed set request 0x0 status: -71
[378573.059447] cp210x ttyUSB0: failed set request 0x0 status: -71
[378573.059456] cp210x ttyUSB0: cp210x_open - Unable to enable UART
[378574.175498] cp210x ttyUSB0: failed set request 0x0 status: -71
[378574.175506] cp210x ttyUSB0: cp210x_open - Unable to enable UART
pi@pi5b:~/actions-runner/_work/tinyusb/tinyusb $ minicom /dev/ttyUSB0