Here you can read the full story: http://forum.armbian.com/index.php/topic/126-fyi-armbian-running-on-a31s-based-banana-pi-m2/?p=2157
And the most funny thing is: A forum member called "sinovoip" (obviously a marketing person without any technical knowlege) posts the 'great news' that the new kernel release 'has support' for the BPi-M2. In fact a linux-sunxi community member wrote a new device tree file for the M2 from scratch because the one SinoVoip provided before was more or less crappy and a result of copy&paste from somewhere else.
That means now official U-Boot and Kernel have good working device tree files while the OS images SinoVoip provides and all their Github repos contain bad ones. And while they advertise the M2 being officially supported they DO NOT exchange their crappy device tree stuff with the 'official' ones from the community. Why?!