chuwi-hi10plus: initial device support

I don't know why but I recently started to do quite some postmarketOS work, now we have another device in the house!

Anyway, this port uses the Android bootloader (kernelflinger) instead of Gummiboot or rEFInd,... just in case if people still wants to easily reflash Android later without going through some DNX Fastboot, Intel Flash Tool blah blah.

More information on this port:

• Chuwi violates GPLv2 by not releasing the kernel sources of Android to the public. And they still does.
• This port uses Linux mainline (5.1-rc7), and almost everything works properly, so thankfully we don't have to use the 3.10 kernel which is outdated and EOL.

Progress:

What works:

• Kernel
• USB networking
• Rootfs
• Wi-Fi
• Bluetooth (not tested, but firmware loads without errors)
• Sound (using PulseAudio)
• Touch (gslx680-ts-acpi)
• 3D Acceleration & Video Decoding
• Both USB ports

What doesn't work:

• Sensors
• SD Card Slot (Sometimes, most of the time it's unreliable)

(anything that isn't mentioned isn't working or not tested)