Move M149 to cpp

Marlin/src/Marlin.cpp

   return false;
 }
 
-#if ENABLED(TEMPERATURE_UNITS_SUPPORT)
-  #include "gcode/units/M149.h"
-#endif
-
 #if HAS_POWER_SWITCH
   #include "gcode/control/M80.h"
 #endif

Marlin/src/gcode/gcode.cpp

 extern void gcode_M119();
 extern void gcode_M120();
 extern void gcode_M121();
-extern void gcode_M149();
 extern void gcode_M150();
 extern void gcode_M163();
 extern void gcode_M164();
       #endif
 
       #if ENABLED(TEMPERATURE_UNITS_SUPPORT)
-        case 149: // M149: Set temperature units
-          gcode_M149();
-          break;
+        case 149: M149(); break;  // M149: Set temperature units
       #endif
 
       #if HAS_COLOR_LEDS

Marlin/src/gcode/units/M149.h → Marlin/src/gcode/units/M149.cpp

  *
  */
 
+#include "../../inc/MarlinConfig.h"
+
+#if ENABLED(TEMPERATURE_UNITS_SUPPORT)
+
+#include "../gcode.h"
+
 /**
  * M149: Set temperature units
  */
-void gcode_M149() {
+void GcodeSuite::M149() {
        if (parser.seenval('C')) parser.set_input_temp_units(TEMPUNIT_C);
   else if (parser.seenval('K')) parser.set_input_temp_units(TEMPUNIT_K);
   else if (parser.seenval('F')) parser.set_input_temp_units(TEMPUNIT_F);
 }
+
+#endif // TEMPERATURE_UNITS_SUPPORT