drm/amd/display: fix clock sequence logic for DCN32

[Why&How]
The newer commit sequence on DCN32 onwards did not finish clock
optimization sequence since the newer sequence did not end up calling
dc_post_update_surfaces_to_stream() which resets dc->optimized_required.

Call this function before passing control on to the new commit sequence.

Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>