density - update for SWTimer api change

examples/main_density.cc

@@ -138,7 +138,7 @@ namespace Heck {
 
 
             scan_pots.set_period(10);
-            scan_pots.set_callback([]() {
+            scan_pots.set_callback([](u32 time_now) {
                 pot1.on_change_fuzzy(seed.adc.Get(0), 10, [](int val) {
                     pots_value[0] = float(val) / (float)std::numeric_limits<u16>::max();
                     density.params[0] =  (pots_value[0] * 5.f) - 1.f;
@@ -166,7 +166,7 @@ namespace Heck {
 
             SWTimer heartbeat{};
             heartbeat.set_period(100);
-            heartbeat.set_callback([&heartbeat_led_state]() {
+            heartbeat.set_callback([&heartbeat_led_state](u32 time_now) {
                 heartbeat_led_state = !heartbeat_led_state;
                 seed.SetLed(heartbeat_led_state);
                 return;