Move M226 to cpp

Marlin/src/Marlin.cpp

   return false;
 }
 
-#include "gcode/control/M226.h"
-
 #if ENABLED(EXPERIMENTAL_I2CBUS)
   #include "gcode/feature/i2c/M260_M261.h"
 #endif

Marlin/src/gcode/control/M226.h → Marlin/src/gcode/control/M226.cpp

  *
  */
 
+#include "../gcode.h"
+#include "../../Marlin.h" // for pin_is_protected and idle()
+#include "../../module/stepper.h"
+
 /**
  * M226: Wait until the specified pin reaches the state required (M226 P<pin> S<state>)
  */
-void gcode_M226() {
+void GcodeSuite::M226() {
   if (parser.seen('P')) {
     const int pin_number = parser.value_int(),
               pin_state = parser.intval('S', -1); // required pin state - default is inverted

Marlin/src/gcode/gcode.cpp

 extern void gcode_M163();
 extern void gcode_M164();
 extern void gcode_M165();
-extern void gcode_M226();
 extern void gcode_M240();
 extern void gcode_M250();
 extern void gcode_M260();
         M221();
         break;
 
-      case 226: // M226: Wait until a pin reaches a state
-        gcode_M226();
-        break;
+      case 226: M226(); break;    // M226: Wait until a pin reaches a state
 
       #if HAS_SERVOS
         case 280: // M280: Set servo position absolute