WIP: Initial support for Huawei Google Nexus 6P (Angler)

Created by: zhuowei

This uses the LineageOS 14.1 kernel.

Currently this produces a fastboot boot-able boot.img-huawei-angler, and telnetting into the initramfs works. However, the splash screen does not work - I will have to look at how other Snapdragon devices initialize screens; I may need to enable the workaround used on Nexus 5.

I have not flashed the root partition yet, so I've only tested the initramfs for now.

Here's the pmOS_init.log:

/ # cat pmOS_init.log 
### postmarketOS initramfs ###
Setup usb network
mkdir: can't create directory '/config/usb_gadget/g1/functions/rndis.usb0': Function not implemented
ln: /config/usb_gadget/g1/configs/c.1/rndis.usb0: No such file or directory
sh: write error: Resource busy
Start the dhcpcd daemon (forks into background)
---
WARNING: usb shell is active on 172.16.42.1:24.
This is a security hole! Only use it for debugging, and
uninstall the usb-shell hook afterwards!
---
fbsplash: can't open console
ERROR: boot partition not found!
fbsplash: can't open console
/ #