rename so nobody is confused that this is just the codec interface

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@11667 d0543943-73ff-0310-b7d9-9358b9ac24b2

diff --git a/src/mod/codecs/mod_dahdi/mod_dahdi.c b/src/mod/codecs/mod_dahdi_codec/mod_dahdi_codec.c
similarity index 100%
rename from src/mod/codecs/mod_dahdi/mod_dahdi.c
rename to src/mod/codecs/mod_dahdi_codec/mod_dahdi_codec.c