drm/amd/display: Revert noisy assert messages

This partially reverts
commit 4fb48bb66211 ("dc: fix split viewport rounding error").

Signed-off-by: Jordan Lazare <Jordan.Lazare@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>