drm/amd/display: fix unbounded requesting for high pixel rate modes on dcn315

Unbounded requesting is getting configured for odm mode calculations which
is incorrect. This change checks whether mode requires odm ahead of time.

Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>