Switch to mmr_event_t based monitoring

The switch is necessary because Multimedia for QNX 7.0.0 removes
support for PPS based monitoring.  PPS itself is deprecated in QNX
7.0.0.  QNX 6.6.0 is also switched to mmr_event_t based monitoring
since Multimedia for QNX 6.6.0 also supports that type of monitoring.

[ChangeLog][QNX] Switch to mmr_event_t based monitoring.  PPS based
monitoring is not supported by Multimedia for QNX 7.0.0.

Change-Id: Id3ce1d8895e8ce492ecdd49cbe88ef5f0d6b0194
Reviewed-by: Michael Brasser <michael.brasser@live.com>
Reviewed-by: Christian Stromme <christian.stromme@qt.io>