The Odroid-C2's processor is fast enough to compile the Linux kernel on it natively, and as such, taking this path should eliminate the complexity involved in cross-compilation.
Depending on the distro you are running, and the packages you have installed, you might need to add the compiler and other build-related tools. For example, a minimal base Debian image would not have gcc, since an embedded Linux appliance generally has no requirement to be used as a development tool. This item shows how to install what you need: Adding Native Compiler and Tools