How to enable CAN devices using buildroot

Hello,
Hopefully some simple questions for more experienced users

I am using buildroot to build a Kernel and file system for Beaglebone Black. I’m using mainline Kernel 4.0 with omap2plus_defconfig and added the Network support for CAN i found in https://groups.google.com/d/msg/beagleboard/ZP8IxIUqEUI/nenpcSgXgmUJ . So far I get a running System with my current configuration.
What i want to do is enabling CAN Bus on Beaglebone Black. As far as I know I need to modify the am335x-boneXXX.dts files in linux-4.0/arch/arm/boot/dts to tell linux that there is a CAN device. Is this correct?
What do I have to add in which .dts File?

Afterwards I hope to be able to continue with


# modprobe can 
# modprobe can-dev 
# modprobe can-raw

# ip link set can0 up type can bitrate 500000

Best regards,
Mike