The VESA Organization Vendor-Specific Data Block, defined in VESA
DisplayID Standard v2.0, specifies the eDP Multi-SST Operation (MSO)
stream count and segment pixel overlap.

DisplayID v1.3 has Appendix B: DisplayID as an EDID Extension,
describing how DisplayID sections may be embedded in EDID extension
blocks. DisplayID v2.0 does not have such a section, perhaps implying
that DisplayID v2.0 data should not be included in EDID extensions, but
rather in a "pure" DisplayID structure at its own DDC address pair
A4h/A5h, as described in VESA E-DDC Standard v1.3 chapter 3.

However, in practice, displays out in the field have embedded DisplayID
v2.0 data blocks in EDID extensions, including, in particular, some eDP
MSO displays, where a pure DisplayID structure is not available at all.

Parse the MSO data from the DisplayID data block. Do it as part of
drm_add_display_info(), extending it to parse also DisplayID data to
avoid requiring extra calls to update the information.

v2: Check for VESA OUI (Ville)
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Acked-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/73ca2887e7b37880690f5c9ba4594c9cd1170669.1630419362.git.jani.nikula@intel.com