Apply #pragma once, misc cleanup (#12322)

* Apply #pragma once in headers
* Adjust some thermistors formatting
* Misc cleanup and formatting

Marlin/src/module/servo.h

@@ -19,14 +19,12 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
+#pragma once
 
 /**
  * module/servo.h
  */
 
-#ifndef _SERVO_H_
-#define _SERVO_H_
-
 #include "../inc/MarlinConfig.h"
 #include "../HAL/shared/servo.h"
 
@@ -40,5 +38,3 @@ extern void servo_init();
   #define DEPLOY_Z_SERVO() MOVE_SERVO(Z_PROBE_SERVO_NR, servo_angles[Z_PROBE_SERVO_NR][0])
   #define STOW_Z_SERVO() MOVE_SERVO(Z_PROBE_SERVO_NR, servo_angles[Z_PROBE_SERVO_NR][1])
 #endif
-
-#endif // _SERVO_H_