Make AX.25, DMR, P25, NXDN and FM selectable at compile time.

DMRDMOTX.cpp

@@ -19,6 +19,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_DMR)
+
 #include "Globals.h"
 #include "DMRSlotType.h"
 
@@ -161,3 +164,5 @@ void CDMRDMOTX::setTXDelay(uint8_t delay)
     m_txDelay = 1200U;
 }
 
+#endif
+