As far as I know it's just just a standard c source file in the drivers/rtc folder in the 4.4 kernel source. It's just a matter of including it in the kernel build. I used menu config for this purpose.
I also tried to get 1wire working but not sure if the tinkerboard actually has the hardware for this. I managed to build the modules on a previous kernel I compiled myself but I think it needs configuring to work with the appropriate gpio pin in the device tree.
Thank you for your quick response and I am certainly loving the armbian build for the tinker board. The graphics is the highlight for me as asus implementation if you want to call it that was very sketchy and was glitching out and artefacting on my panasonic tv on the latest build.
By the way I am still researching the device tree overlays too but it seems quite complicated. I'll continue reading further about this topic.
Keep up the great work