drm/amd/display: Disconnect DCN2 mpcc when changing tg

A previous fix was done for DCN1 that needed to be ported to DCN2:
commit 60c677534e73 ("drm/amd/display: Disconnect mpcc when changing tg")
Signed-off-by: Leo Li <sunpeng.li@amd.com>
Acked-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c

@@ -1323,9 +1323,10 @@ static void dcn20_apply_ctx_for_surface(
 			}
 		}
 
-		if (!pipe_ctx->plane_state &&
-			old_pipe_ctx->plane_state &&
-			old_pipe_ctx->stream_res.tg == tg) {
+		if ((!pipe_ctx->plane_state ||
+		     pipe_ctx->stream_res.tg != old_pipe_ctx->stream_res.tg) &&
+		     old_pipe_ctx->plane_state &&
+		     old_pipe_ctx->stream_res.tg == tg) {
 
 			dc->hwss.plane_atomic_disconnect(dc, old_pipe_ctx);
 			removed_pipe[i] = true;