codec_dahdi: DAHDI still advertises formats using the old bitfields.

Previously, the DAHDI format bit fields matched up with the Asterisk
bitfields. Since the Asterisk codec bit fields were replaced in r306010,
codec_dahdi needs to contain the formats itself. In the future, the DAHDI
formats should either change to something other than bitfields, or the
bitfields need to move from include/dahdi/kernel.h to
include/dahdi/user.h.

Signed-off-by: Shaun Ruffell <sruffell@digium.com>

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@314471 65c4cc65-6c06-0410-ace0-fbb531ad65f3