drm/amd/display: Add missing post flip calls

drm/amd/display: Add missing post flip calls

[WHY&HOW]
dc_post_update_surfaces_to_stream needs to be called after a full update
completes in order to optimize clocks and watermarks for power. Add
missing calls before idle entry is requested to ensure optimal power.

Reviewed-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Dillon Varone <Dillon.Varone@amd.com>
Signed-off-by: Ivan Lipski <ivan.lipski@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>