video/hdmi: Hook the HDMI vendor infoframe with the generic _pack()

With this last bit, hdmi_infoframe_pack() is now able to pack any
infoframe we support.

At the same time, because it's impractical to make two commits out of
this, we get rid of the version that encourages the open coding of the
vendor infoframe packing. We can do so because the only user of this API
has been ported in:

  Author: Damien Lespiau <damien.lespiau@intel.com>
  Date:   Mon Aug 12 18:08:37 2013 +0100

      gpu: host1x: Port the HDMI vendor infoframe code the common helpers

v2: Change oui to be an unsigned int (Ville Syrjälä)

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dave Airlie <airlied@gmail.com>