[RFC] Stereo 3D modes support

[Damien Lespiau]

Hi,

This series introduces stereo 3D modes support and is split in 3 chunks:

1. 3 kernel patches to parse the 3D_present flag of the HDMI CEA vendor block,
   to expose 3D formats flags in modes and to add a new property on connectors
   supporting stereo 3D,

2. Sync the new mode flags in libdrm,

3. Use testdisplay from intel-gpu-tools to test the Top Bottom and Frame
   Packing modes,

A few notes:

- An (edited) extract of HDMI 1.4a for 3D formats is available publicly:
   http://www.hdmi.org/manufacturer/specification.aspx

- I tried to come up with a way to not disrupt current user space with extra 3D
  modes. The 3D formats (the different ways of laying out buffers with left and
  right frames) that a mode supports are indicated with flags in mode.flags.
  This also means that no extra mode is added to the mode list, the format flags
  are added on already exposed 2D modes.

- For now, only the 3D_present flags of the CEA HDMI block is being parsed,
  only exposing the then "mandatory" 3D formats (see HDMI 1.4a 3D spec)

- When scanning out a 3D framebuffer, the "select 3D mode" property attached to
  a connector can be used to tell the driver to send the HDMI vendor infoframes
  with the 3D format details.

- 3D test images are available at:
    http://www.quantumdata.com/apps/3D/sample_BMP.asp

- These patches have taken some inspiration from previous work of Armin Reese
  <armin.c.reese at intel.com> and Sateesh Kavuri.

Comments, suggestions and reviews are greatly appreciated!

--
Damien