video: add anx6345 DM driver

This is a eDP bridge similar to ANX9804, it allows to connect eDP panels
to the chips that can output only parallel signal

Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
[agust: fixed most checkpatch errors/warnings]
Signed-off-by: Anatolij Gustschin <agust@denx.de>