drm pixel formats update

[ville.syrjala at linux.intel.com]

I decided to go all out with the pixel format definitions. Added pretty
much all of the possible RGB/BGR variations. Just left out ones with
16bit components and floats. Also added a whole bunch of YUV formats,
and 8 bit pseudocolor for good measure.

I'm sure some of the fourccs now clash with the ones used by v4l2,
but that's life.

If anyone has problems with the way the formats are defined, please
speak up now! Since only Jesse has bothered to comment on my rantings
I can only assume people are happy with my approach to things.

These patches should apply on top of Jesse's v3+v5 set... I think.
I sort of lost track of things when the patches started having
different version numbers. At least we're not yet into two digits
numbers ;)