Pekka Paalanen authored Nov 21, 2018 and Jonas Ådahl committed Jan 30, 2019

These functions allow inspecting which pixel formats a CRTC's primary
plane supports. Future patches will inspect the supported formats and
pick a framebuffer format accordingly instead of hardcoding a format.

The copy list function will be used to initialize a formats list, and
the supports format function will be used to intersect that list against
another CRTC's supported formats.

GNOME/mutter!341