Add missing GTF modes
Add missing GTF modes

A fixed-mode output device like a panel will often only inform of its
preferred mode through its EDID. However, the driver will adjust user
specified modes for display through use of a panel-fitter allowing
greater flexibility in upscaling. This is often used by games to set a
low resolution for performance and use the panel fitter to fill the
screen.

v2: Use the presence of the 'scaling mode' connector property as an
indication that a panel fitter is attached to that pipe.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=55564

wzyy2/xf86-video-modesetting,patjak/xf86-video-gma500,patjak/xf86-video-gma500,wzyy2/xf86-video-modesetting