Bug#983338: RPI-3B+: serial console shows garbage - Steps to reproduce

[Matthias Klein <matthias@extraklein.de>]

Steps to reproduce:

- Build an image using the recipes here: 
https://salsa.debian.org/raspi-team/image-specs
	or download a prebuild image from here: 
https://raspi.debian.net/tested-images/

- connect a 3V3 serial console to pins 6, 8, and 10 on the 40 pin GPIO 
header

- Boot into the system and install the packages:
	apt-get update
	apt-get dist-upgrade
	apt-get install tigervnc-standalone-server xfce4

- Reboot the system
	reboot

- Try to login on the serial console ...
	=> only garbage ...