drm/amd/display: Add check for validating unsupported ODM plus MPO case

[Why]
We do not currently support ODM plus MPO on only one side of the
screen. This unsupported case causes validation calculations to
divide by zero due to invalid viewport values.

[How]
Add stopgap for the validation of ODM plus MPO on one side of
screen case.

Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Jaehyun Chung <jaehyum.chung@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>