added: dtshd_ma and dtshd_hra identifiers for DTS-HD

Add codec identifiers dtshd_ma and dtshd_hra for DTS-HD Master Audio and
DTS-HD High Resolution Audio, respectively.

When built with an old external libavcodec that doesn't support
detecting them, they will continue to be identified as regular "dca".

Note that the channel count and sample rate continue to reflect the rate
of the core substream, which is the one that ffmpeg can decode.