drm/i915: Write AVI infoframes for Parade LSPCON

Different LSPCON vendors specify their custom methods to pass
AVI infoframes to the LSPCON chip, so does Parade tech.

This patch adds functions to arrange and write AVI infoframes
into Parade LSPCON chips.

V2: rebase
V3: Added r-b from Maarten
V4: rebase
V5: rebase
V6: rebase
V7: Fixed checkpatch warnings for alignment
V8: Rebase
V9: Rebase
V10: Rebase

Cc: Imre Deak <imre.deak@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1539325394-20788-7-git-send-email-shashank.sharma@intel.com