Change uart baud rate to 115200

[grant-olson]

It is a well-known problem that the initial programming of the Ox64 is a bit tricky, and many USB-to-UART adapters don't work. Even though I had existing adapters, I still needed to purchase two different chipsets until I could find one that worked.

The CP2102 works, but only at 115200 baud. With the current baud rate of 2000000 I need to switch chips after programming to see the output.

This patch changes the baud rates to a much more standard 115200 baud, which is likely to work with all UART adapters out there.

I think at this point it is best to make it as easy as possible to developers to get their boards up and running, and think this patch removes one obstacle that is making development frustrating.

[gamelaster]

Although you're right about the baudrate and issues with dongles, I don't think it is good idea to lower baudrate, as every Bouffalo chip and firmware uses this baudrate.