codecparsers: vc1: simplify GstVC1VopDquant structure.
Rename dqsbedge to dqbedge. The intent is that we can only have a single
boundary edge selector, depending on the value of dqprofile. So, dqbedge
represents DQSBEDGE if dqprofile == GST_VC1_DQPROFILE_SINGLE_EDGE, or
DQDBEDGE if dqprofile == GST_VC1_DQPROFILE_DOUBLE_EDGE.
The former dqbedge field is marked as unused and can be removed on the
next gst-plugins-bad version that allows ABI changes.
https://bugzilla.gnome.org/show_bug.cgi?id=692272
Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne@intel.com>