Tbeams have no ADC (#4871)

src/Power.cpp

@@ -147,6 +147,8 @@ using namespace meshtastic;
  */
 static HasBatteryLevel *batteryLevel; // Default to NULL for no battery level sensor
 
+#ifdef BATTERY_PIN
+
 static void adcEnable()
 {
 #ifdef ADC_CTRL // enable adc voltage divider when we need to read
@@ -171,6 +173,8 @@ static void adcDisable()
 #endif
 }
 
+#endif
+
 /**
  * A simple battery level sensor that assumes the battery voltage is attached via a voltage-divider to an analog input
  */