kmssink: fallback to universal planes if no overlay plane is found
Without setting the DRM_CLIENT_CAP_UNIVERSAL_PLANES capability bit, only
overlay planes are made available for compatibility with legacy clients.
But if a CRTC doesn't have an overlay plane associated, then kmssink is
not able to find a plane for the CRTC and the pipeline will fail, i.e:
ERROR kmssink gstkmssink.c:482:gst_kms_sink_start:<kmssink0> Could not find a plane for crtc
If no overlay planes were found for a given CRTC, fallback to universal
planes so DRM will also return primary planes that can be used instead.
https://bugzilla.gnome.org/show_bug.cgi?id=768183
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>