[split] U-Boot with NVMe support, keyboard & display working

[belfastraven]

@Arwen to answer your questions:

- Problems with 5.5 and later - very plausible.
- It has booting from everything possible - eMMC, SD, USB and NVME

Let's wait and see how it goes for others.

@samueldr has identified the problem with booting later kernels. You can find details here --> https://github.com/samueldr/wip-pinebook...-664046551

Strangely I have booting problems just occasionaly. And with this last update from Arnaud it happens very rarely.

I am also having problems booting Manjaro with 5.7 kernel.  (on my NVME) but never  a MRfixit image ( from sd )with an earlier kernel.  When I can't boot, the system starts booting but gets stuck in the same place as it did before the latest changes.  The screen get a weird multi-color pattern and then nothing.  The serial console will also hang at that point. 

The booting of different kernels on same device seems to be working fine (I faked it out by pointing to the same kernel with different menu names,  since I have only one on the device...)    I have noticed that when using CTRL-c to interrupt u-boot to boot from a different device,  there is no entry for the NVME  ,  so that if there is an SD card installed one will boot from that,  since it is specified before NVME in the u-boot code.boot order...