hello @captain kirk,
imx219 is supported on tinker board r2.0, i don't think you need to add an overlay, but if you must, try modify the last line:
overlay=CSI0-IMX219
save and then reboot
to test and see if the camera works:
gst-launch-1.0 v4l2src device=/dev/video0 ! video/x-raw,format=NV12,width=640,height=480 ! videoconvert ! autovideosink
reference: Tinker Board (asus.com)