drm/amd/display: Fix DFPstate hang due to view port changed

[Why]
Place the cursor in the center of screen between two pipes then
adjusting the viewport but cursour doesn't update cause DFPstate hang.

[How]
If viewport changed, update cursor as well.

Cc: stable@vger.kernel.org
Signed-off-by: Paul Hsieh <paul.hsieh@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1457,8 +1457,8 @@ static void dcn20_update_dchubp_dpp(
 
 	/* Any updates are handled in dc interface, just need to apply existing for plane enable */
 	if ((pipe_ctx->update_flags.bits.enable || pipe_ctx->update_flags.bits.opp_changed ||
-			pipe_ctx->update_flags.bits.scaler || pipe_ctx->update_flags.bits.viewport)
-			&& pipe_ctx->stream->cursor_attributes.address.quad_part != 0) {
+			pipe_ctx->update_flags.bits.scaler || viewport_changed == true) &&
+			pipe_ctx->stream->cursor_attributes.address.quad_part != 0) {
 		dc->hwss.set_cursor_position(pipe_ctx);
 		dc->hwss.set_cursor_attribute(pipe_ctx);