Factor out bus configuration

lib/comms/comms.h

@@ -5,14 +5,9 @@
 #include <LoRaBoards.h>
 
 #include <LiLyGo.h>
+#include <bus.h>
 #include <config.h>
 
-#ifndef ARDUINO_USB_CDC_ON_BOOT
-#define SERIAL0 Serial
-#else
-#define SERIAL0 Serial0
-#endif
-
 #ifndef SCAN_MAX_RESULT_KHZ_SCALE
 // kHz scale: round frequency, so it fits into 2 bytes
 // 2500000 / 40 = 62500, scale 40 fits 2.5GHz into two bytes
@@ -135,7 +130,7 @@ struct Comms
 
 struct NoopComms : Comms
 {
-    NoopComms() : Comms("no-op", SERIAL0) {};
+    NoopComms() : Comms("no-op", Uart0) {};
 
     virtual bool send(Message &) { return true; };
     virtual void _onReceive() {};