this isn't a MPC5500 support list, but one doesn't exist yet. The MPC5554 is currently only supported to select customers outside of the Automotive market.
However, the eTPU is available on on a general market Coldfire device. therefore, there is an eTPU product page on the external Freescale web site (http://www.freescale.com/eTPU <http://www.freescale.com/eTPU> ). on this page there are many application notes on different eTPU functions. I don't see an application note for the Pulse and Frequency Measurement function, but there is source code for the function.