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

I just wrote the bits to define and pack HDMI vendor specific infoframe.
Port the host1x driver to use those so I can refactor the infoframe code
a bit more.

This changes the length of the infoframe payload from 6 to 5, which is
enough for the "frame packing" stereo format.

v2: Pimp up the commit message with the note about the length
    (Ville Syrjälä)

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Terje Bergström <tbergstrom@nvidia.com>
Cc: linux-tegra@vger.kernel.org

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