add icarus to hotplug

cgminer.c

@@ -7052,6 +7052,10 @@ static void *hotplug_thread(void __maybe_unused *userdata)
 			new_devices = 0;
 			new_threads = 0;
 
+#ifdef USE_ICARUS
+			icarus_drv.drv_detect();
+#endif
+
 #ifdef USE_BFLSC
 			bflsc_drv.drv_detect();
 #endif