pcm_bluray: rename pcm-mpeg.c to pcm-bluray.c

The original idea was to collect PCM codecs that could appear in various
MPEG streams in this file. Discussion in IRC lead to the conclusion that
one codec per file would be better and stop the need for #ifdefs.
Merge commit '0d6549d8b57aaa5be8efb794154cdbe9a645910f'

* commit '0d6549d8b57aaa5be8efb794154cdbe9a645910f':
  pcm_bluray: rename pcm-mpeg.c to pcm-bluray.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>