ecore_audio: fix distribution of eolian files
When a 'make dist' is executed on a repository that does not have
CoreAudio support, eolian files required for CoreAudio compilation will
not be distributed, making the source distribution incompatible where
CoreAudio is required.
There is the same potential issue for pulseaudio, but as it is a basic
requirement, it is likely to always have been distributed because the
distribution was always created from a base which enabled pulseaudio.
This allows to produce on Linux a sources tarball usable on Mac OS X.
@fix