BeagleBone Black Device Tree overlay : Could not find symbol 'ocp'

Just got my BBB 2 days ago, and immediately replace Angstrom with ArchLinux ARM following the procedures on the BBB page, and it boots up without any problems. I have a BeagleBone White works flawlessly with Archlinux ARM, but I am a total noob to Device Tree, so when I try to enable the GPIO following the video made by Derek Molloy, something is wrong.

First, I tried to compile DM-GPIO-Test.dts

`
/*

Downgrade the kernel to 3.8.