how to enable /dev/i2c-0 on 0x64

[donadams]

Hi All, I've ran through this tut https://wiki.pine64.org/wiki/Ox64 and flashed my board. Along the way I enabled the i2c options in the buildroot menu but I don't see "/dev/i2c-0 " when booted. I also don't see i2c kernal msgs (not sure if there should be?). i2ctools is installed.
Wondering if anyone knows what the next step is from there? Is there a device tree that needs to be updated?
Thanks