[Cleanup] Remove not working stereo to mono split mode/setting.

Conflicts:
	xbmc/video/dialogs/GUIDialogAudioSubtitleSettings.cpp
[pvr] fix wrong printf format mismatch
Merge pull request #5027 from ace20022/rem_stereo_to_mono

[Cleanup] Remove broken stereo to mono split mode/setting.
Merge pull request #5405 from xhaggi/pvr-fix-printf-format-mismatch

[pvr] fix wrong printf format mismatch