[RFC] drm: add overlays as first class KMS objects

[Alan Cox]

> I was planning on adding a new fb ioctl to allow us to create fbs with
> specific surface format types.  We could either enumerate all of the
> ones we support (a list which will grow as drivers and devices are
> added) or try to factor out commit bits into a separate surface struct:
> 
> struct drm_mode_surface {
> 	enum components; /* YUV, VUY, RGB, BGR, ARGB, ... */
> 	int depth;
> 	enum packing; /* some list of packing types? */
> 	...
> };


Any reason for not just using the Video4Linux 2 formats here, they've
been enumerating video formats for some time already.