That one should work for things where you build up a new system in the /mnt/us file tree like you did with the K3.
For things which must be compatible with the K5's standard set of libraries - -
It should be possible to disable the hard float, the VFP3 (in favor of the VFP), disable the neon instructions ....
and whatever else makes the code in-compatible with the K5's standard set of libraries.
It should be easier this time (for the K5) because the tool-chain and the target device both use the eglibc system libraries.