drm/edid: Fill PAR in AVI infoframe based on CEA mode list

Populate PAR in infoframe structure. If there is a user setting for PAR, then
that value is set. Else, value is taken from CEA mode list if VIC is found.
Else, PAR is calculated from resolution. If none of these conditions are
satisfied, PAR is NONE as per initialization.

v2: Removed the part which sets PAR according to user input, based on
Daniel's review comments.

A separate patch will be submitted to create a property that would enable a
user space app to set aspect ratio for AVI infoframe.

v2: Removed the part which sets PAR according to user input, based on
Daniel's review comments.

v3: Removed calculation of PAR for non-CEA modes as per discussion with
Ville.

A separate patch will be submitted to create a property that would enable a
user space app to set aspect ratio for AVI infoframe.

Signed-off-by: Vandana Kannan <vandana.kannan@intel.com>
Cc: Jesse Barnes <jesse.barnes@intel.com>
Cc: Vijay Purushothaman <vijay.a.purushothaman@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: intel-gfx@lists.freedesktop.org
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
[danvet: Squash in fixup for htmldocs.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>