Apply #pragma once, misc cleanup (#12322)

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

Marlin/src/core/utility.h

@@ -19,9 +19,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
-
-#ifndef __UTILITY_H__
-#define __UTILITY_H__
+#pragma once
 
 #include "../inc/MarlinConfigPre.h"
 
@@ -102,5 +100,3 @@ void safe_delay(millis_t ms);
 #if ENABLED(DEBUG_LEVELING_FEATURE)
   void log_machine_info();
 #endif
-
-#endif // __UTILITY_H__