Dave Airlie authored Oct 14, 2014 and Bastien Nocera committed Jul 01, 2015

This adds the interfaces to allow for tiled
monitor support via gnome-desktop.

1) add output config get/set tiled geometry/rotation support

These hide under the standard APIs, and just set the
state for the tiled outputs by setting the primary
tile up.

2) add output config API to get primary tile

3) add tile flags to modes - add gather function
to create tiled modes for primary outputs.

https://bugzilla.gnome.org/show_bug.cgi?id=750311