drm/amd/display: update fullscreen status to SPL

[Why]
Current fullscreen check in SPL using dm_helpers is out-of-sync
with dc state. This causes an issue during minimal transition
where we pick an invalid intermediate state because the pre and
post fullscreen status are different.

[How]
Add sharpening_required flag to dc_stream_state. Use this flag to
indicate if we are in fullscreen or not. Propagate flag to SPL for
fullscreen status. Remove workaround in DML

Reviewed-by: Alvin Lee <alvin.lee2@amd.com>
Signed-off-by: Samson Tam <Samson.Tam@amd.com>
Signed-off-by: Wayne Lin <wayne.lin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>