Correct c_offload_node_time_scaled value on HW by using real.

applications/lofar2/libraries/sdp/src/vhdl/sdp_statistics_offload.vhd

@@ -174,8 +174,12 @@ architecture str of sdp_statistics_offload is
   constant c_nof_streams               : natural := 1;
 
   -- Offload timing
-  constant c_offload_node_time_scaled : natural := (g_offload_node_time * 2**g_offload_scale_w) /
-                                                    g_ctrl_interval_size_min;
+  -- . use natural(real()) to avoid overflow due to intermediate natural result 600000 * 2**15 > 2*31
+  --   - natural: 600000 * 2**15 / 20000000 = -90 (from compile or sim load error message)
+  --   - real: 600000 * 2**15 / 20000000 = 983.04 --> 983
+  constant c_offload_node_time_scaled : natural := natural(real(g_offload_node_time) *
+                                                           real(2**g_offload_scale_w) /
+                                                           real(g_ctrl_interval_size_min));
   constant c_offload_packet_time_scaled : natural := (g_offload_packet_time * 2**g_offload_scale_w) /
                                                       g_ctrl_interval_size_min;
   constant c_offload_packet_time_max : natural := g_offload_packet_time *