feat: add support for RadioMaster TX16S MK3 (#7017)

Co-authored-by: philmoz <phil.a.mitchell@gmail.com>
Co-authored-by: 3djc <3djc@gh.com>
Co-authored-by: Peter Feerick <5500713+pfeerick@users.noreply.github.com>

radio/src/mixer.cpp

@@ -31,6 +31,10 @@
 #include "hal/switch_driver.h"
 #include "hal/audio_driver.h"
 
+#if defined(LUMINOSITY_SENSOR)
+#include "luminosity_sensor.h"
+#endif
+
 #define DELAY_POS_MARGIN   3
 
 uint8_t s_mixer_first_run_done = false;
@@ -403,6 +407,12 @@ getvalue_t _getValue(mixsrc_t i, bool* valid)
     return RESX;
   }
 
+#if defined(LUMINOSITY_SENSOR)
+  else if (i == MIXSRC_LIGHT) {
+    return getLuxSensorValue() - RESX;
+  }
+#endif
+
   else if (i <= MIXSRC_LAST_HELI) {
 #if defined(HELI)
     return cyc_anas[i - MIXSRC_FIRST_HELI];