Hi,
For the bleeding edge, you can use the latest linux-next branch:
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/
It reflects what will be linux-4.12-rc1 in 3 weeks.
But you may need something safer by either using:
https://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux-amlogic.git/log/?h=v4.12/integ
which is the ARM Amlogic maintainer integration tree, but without HDMI.
Or you can also use my 4.10 + backports Yocto layer:
Which has almost everything in 4.11 + HDMI + audio but may lack some stuff pushed for 4.12