K-worker creates load on Allwinner devices
If no display is connected to a sunxi system, the module sun4i_drm_hdmi will scan every 5 to 10 seconds for a hdmi display. As this needs significant time, a load spike of around 20% can be seen. On a headless system this is not desirable. Unfortunately the module cannot be blacklisted as it is not compiled as a module in the armbian kernel configuration. This update changes the kernel configuration to compilation as a module. Configuration for sunxi (legacy, current, dev) and for sunxi64 (legacy, current, dev) is updated (based on kconfig). Successful build was tested with building legacy, current and dev kernels for cubieboard and pine64.