drm/amd/display: Change AVI Info Frame version to 4 for OVT

[Why]
Official Release CTA specification reverted the change and
no longer uses version 5 to indicate OVT timing.

[How]
Change the version used for AVI info Frame for OVT to 4.

Reviewed-by: Leo Ma <hanghong.ma@amd.com>
Acked-by: Zaeem Mohamed <zaeem.mohamed@amd.com>
Signed-off-by: Chris Park <chris.park@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>