Fix DVD resume: accept .IFO files regardless of file name case
Also accept Video CD files regardless of case
[rbp/omxplayer] Remove unused state from OMXClock

m_has_audio/m_has_video are always set before OMXReset is called, so just make them local parameters.
m_video_start and m_audio_start are unused, so remove them.

This commit should have no functional change