Changes

trau_frame cosmetic: rm dead/invalid definitions

All 3 module-internal C preprocessor definitions removed here have
never been used, and it is not clear where or how they were ever
intended to be used.  (The present trau_frame layer is concerned with
low-level de/encoding; high-level de/encoding of AMR frames happens in
the new AMR TRAU frame interworking facility.)  Furthermore, one of
these never-used preprocessor definitions expands to invalid C code.
Remove the bogon.

Change-Id: Icd96220455888ec5e1d03402b750da6945aaf095