Mainline-bsp image creation

Decided to make a rockpi4 mainline automated image build

sudo apt-get update && sudo apt-get upgrade
sudo apt-get install git

Clone the source code

cd ~
git clone --recursive

Just got the skeleton in and deliberately trying to make it much simpler than the spaghetti of the 4.4 bsp.
Clone, copy and contribute as will prob be scratching my head!