Apply #pragma once, misc cleanup (#12322)

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

Marlin/src/HAL/HAL_AVR/endstop_interrupts.h

@@ -19,6 +19,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
+#pragma once
 
 /**
  * Endstop Interrupts
@@ -35,9 +36,6 @@
  * (Located in Marlin/buildroot/share/pin_interrupt_test/pin_interrupt_test.ino)
  */
 
-#ifndef _ENDSTOP_INTERRUPTS_H_
-#define _ENDSTOP_INTERRUPTS_H_
-
 #include "../../core/macros.h"
 #include <stdint.h>
 #include "../../module/endstops.h"
@@ -256,5 +254,3 @@ void setup_endstop_interrupts( void ) {
 
   // If we arrive here without raising an assertion, each pin has either an EXT-interrupt or a PCI.
 }
-
-#endif // _ENDSTOP_INTERRUPTS_H_