Closes #6

This is a somewhat breaking change, and a difference compared to:

• Vendor ecosystem
• U-Boot detaults (cc Document differences compared to U-Boot #32)

But conversely, this harmonizes our boards. All boards now will use the same exact serial settings.

Additionally, as was discovered, TF-A already sets it to 115200

• https://developer.trustedfirmware.org/T762
• https://github.com/ARM-software/arm-trusted-firmware/blob/8078b5c5a0c2a47710df96412d88df53486e2b29/plat/rockchip/rk3399/rk3399_def.h#L20

So it's not out of the question to do it here too.

Finally, some distros will assume 115200 on serial for getty by default. This will help in these cases.

TODO

Test on:

• ROC-RK3399-PC
• Pinebook Pro

Then:

• Add documentation about that (General gist: serial.md title: Accessing the serial console)