VoiceCall: Make it work without Mer specific bits
Other distros such as LuneOS uses VoiceCall as well. To date LuneOS was always maintaining patches to make sure that the Mer specific bits not available in LuneOS were disabled.
Made the code more flexible so Voicecall can be used by simply enabling or disabling some flags in the build and in this way a single codebase can be shared between Mer and LuneOS for Voicecall.
Signed-off-by: Herman van Hazendonk firstname.lastname@example.org