4ded184268Makefile: Add support for RPi3; add param VERSION
Before the targets were split by RPi version (install-rpi1, install-rpi2
etc), now there is only one target for each action and the VERSION
parameter must be specified (install VERSION=2).
c983359f6asrc-rpi3: Add RPi3 boot/config and empty pkg cache
8e125c4d9cboot/config-universal: Disable overscan like in curr config.txt