drm/amd/display: determine if a pipe is synced by plane state

[why]
is_blanked is not a general indicator of if a pipe is synced
for all asics.
plane state is more accurate and applicable for all asics.

[how]
Remove is_blanked call and
add checking plane_state against NULL instead.
Signed-off-by: NWenjing Liu <Wenjing.Liu@amd.com>
Reviewed-by: NTony Cheng <Tony.Cheng@amd.com>
Acked-by: NBhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/core/dc.c

@@ -907,11 +907,11 @@ static void program_timing_sync(
 			}
 		}
 
-		/* set first unblanked pipe as master */
+		/* set first pipe with plane as master */
 		for (j = 0; j < group_size; j++) {
 			struct pipe_ctx *temp;
 
-			if (pipe_set[j]->stream_res.tg->funcs->is_blanked && !pipe_set[j]->stream_res.tg->funcs->is_blanked(pipe_set[j]->stream_res.tg)) {
+			if (pipe_set[j]->plane_state) {
 				if (j == 0)
 					break;
 
@@ -922,9 +922,9 @@ static void program_timing_sync(
 			}
 		}
 
-		/* remove any other unblanked pipes as they have already been synced */
+		/* remove any other pipes with plane as they have already been synced */
 		for (j = j + 1; j < group_size; j++) {
-			if (pipe_set[j]->stream_res.tg->funcs->is_blanked && !pipe_set[j]->stream_res.tg->funcs->is_blanked(pipe_set[j]->stream_res.tg)) {
+			if (pipe_set[j]->plane_state) {
 				group_size--;
 				pipe_set[j] = pipe_set[group_size];
 				j--;