Make code implementation conditionally built for RaspberryPI because
OMX_IndexConfigAudioRenderingLatency seems to be a Broadcom extension.
On other targets the query position might not be accurate without
implementing _delay appropriatelly.
Provides omxanalogaudiosink and omxhdmiaudiosink elements on
the Raspberry PI.
- omxanalogaudiosink is capable to render raw mono or stereo audio
through the jack output.
- omxhdmiaudiosink is capable to render raw audio up to 8 channels
and transmit ac3/dts(IEC 61937) through the HDMI output.
- sinks provide a clock derived from rendered samples
- sinks support the GstStreamVolume interface by implementing
the volume and mute properties.
https://bugzilla.gnome.org/show_bug.cgi?id=728962
